Diaphragm Valve Manufacturer

NTVAL offers durable Diaphragm Valves designed for large-scale industrial projects. Built for precise fluid control, they minimize maintenance and downtime. Our valves provide reliable performance in critical applications, supported by expert engineering and service.

Reliable Diaphragm Valve

Diaphragm valves are named after the flexible disc, or diaphragm, that interacts with a seat at the top of the valve body to create a seal. The diaphragm, which is a pressure-sensitive component, can move to open, close, or regulate the valve. Unlike pinch valves, diaphragm valves use an elastomeric diaphragm to separate the flow stream from the closure element, providing reliable control over the flow.
 
  • Selection Tip: Be aware that there is also an automated valve with a diaphragm-type actuator that has a similar name. It’s important to confirm the specific type of valve referred to by the manufacturer to avoid confusion.
  • Classification: A diaphragm valve is a linear motion valve that is used to start/stop and control fluid flow.
Diaphragm Valve 1

Quality Control

PMI Test

Sealing Test

Low Emission Test

Impact Test

Dimension Inspection

Painting Thickness Test

PT

Material Inspection

Our Valve Applications in Key Industries

Discover how our advanced valve solutions improve flow control, delivering enhanced efficiency, safety, and strict quality assurance.

Chemical Processing

Petrol Chemical

O.P.G & Nuclear

Pulp

Mining

Water & Sewage

Steam System

Boiling System

Get More Versatile Valve

Method Of Control

AdvantagesDisadvantages
Extremely clean

Can only be used in moderate temperature

(-60 to 450°F)

Leak proof seal

Can only be used in moderate pressures

(approximately 300psi)

Tight shut-offCannot be used in multi-turn operations
Easy maintenanceNo industry standard face-to-face dimensions
Repairs can be made without interrupting pipelineThe body must be made of corrosive resistant material
Reduce leakage to the environment 
Diaphragm valves operate using a flexible diaphragm connected to a compressor by a stud molded into the diaphragm. Unlike pinch valves, which pinch the liner to shut off the flow, diaphragm valves achieve shut-off by pressing the diaphragm against the bottom of the valve body. This design provides a reliable seal and effective control over the flow of media.
 
Manual diaphragm valves are excellent for controlling flow because they allow for precise adjustments. The handwheel is turned to adjust the opening, regulating the pressure drop through the valve. For start and stop operations, the handwheel is used to either press the diaphragm down to block flow or lift it to allow flow to pass through the system.

Diaphragm Valve Function

Diaphragm Connection
The diaphragm is connected to a compressor by a stud molded into the diaphragm.
Starting or Increasing Flow
The compressor is lifted by the valve stem to start or increase flow.
Stopping or Slowing Flow
The compressor is lowered, pressing the diaphragm against the bottom of the valve to stop or slow down the flow.
Versatility
Diaphragm valves are ideal for controlling fluids that contain suspended solids and offer the flexibility of being installed in any position.
Throttling Capability
Weir-type diaphragm valves are better for throttling due to their large shutoff area along the seat, which provides quick-opening characteristics.
Leak Prevention
The diaphragm acts as a gasket, sealing the valve to prevent leaks between the body and the bonnet cap.

Types of Diaphragm Valves

Diaphragm valves are available in 2 basic forms. The basic construction of both valves is similar except for the body and diaphragm:

Weir-Type

Weir-type diaphragm valves are the most popular and are best suited for general use, especially in corrosive or abrasive environments. They are ideal for controlling small flows and feature a raised lip on the body that the diaphragm contacts. Because the diaphragm does not need to stretch as far, it can be made of heavier material, making these valves suitable for high-pressure and vacuum services.
 
The weir design includes a 2-piece compressor component that allows for precise control. Initially, only the central part of the diaphragm lifts, creating a small opening. As the valve continues to open, both the inner and outer compressor components lift, providing additional throttling similar to other valve types.
Diaphragm Valve 8
Diaphragm Valve 9

Straight-Through

Straight-through diaphragm valves are useful when the flow direction changes within the system. The flat-bottom design of the valve body allows for unobstructed flow, making it ideal for use with sludge, slurries, and other thick fluids. However, because the diaphragm needs to be flexible enough to reach the bottom, it may have a shorter lifespan and is not well suited for high-temperature fluids.

Media

Category

Description

Flow Control and Maintenance

Products designed to control, maintain, and regulate the flow of materials through hoses, pipes, or tubing. These materials can be liquid, gaseous, or semi-solid (such as colloids and slurries).

Flow Measurement and Monitoring

Devices used to measure and monitor the flow, level, density, specific gravity, and viscosity of materials.

Product Families

  • Valves
  • Valve actuators and positioners
  • Dispensing valves
  • Pumps
  • Flow sensors
  • Level sensors
  • Density and specific gravity sensors
  • Viscosity sensors
  • Miscellaneous related products

Applications

Diaphragm valves are ideal for handling corrosive fluids, fibrous slurries, radioactive fluids, or other materials that must remain uncontaminated. The diaphragm prevents direct contact with the media, making these valves suitable for sticky or viscous fluids that might clog other valve types.

Valve Components

Diaphragm valves have a simple body construction. Here are the following:
 
Diaphragm Valve 10

Body

Stem

  • Non-Indicating Stem: In this design, the stem does not rotate but moves up and down when the handwheel rotates a bushing. The diaphragm, attached to the compressor, moves accordingly. Non-indicating bodies can use sealed bonnets with a seal bushing.
  • Indicating Stem: Similar to the non-indicating design, but the stem is longer and extends through the handwheel, allowing for visual indication. Indicating bodies can also use a sealed bonnet with a seal bushing and O-ring.

Bonnet

The bonnet covers the top of the valve, housing the non-wetted parts, the compressor, and the handwheel mechanism. Bonnet designs can be quick-opening and lever-operated, interchangeable with standard bonnets on weir-type bodies. Larger valves used in vacuum services might require a sealed, evacuated bonnet.

Compressor

The compressor operates the diaphragm and is located above it, under the handwheel stem. Shaped like the valve’s flow passage, the compressor is essential for controlling the diaphragm’s movement.

Actuator

The valve actuator is responsible for moving the stem and disc to open or close the valve. Different types of actuators are available, each suited to specific system needs, such as the required torque, speed, and whether automatic operation is necessary. Some actuators provide additional features, like adjustable openings, precise flow control with positioners, and electric relays to indicate the valve’s position.
Manual Actuators
Manual actuators use a handwheel or crank to open or close the valve. These are ideal for remote systems without power access but are less practical for large valves. Gearheads can be added to increase mechanical advantage and adjust the open/close speed.
Electric Motor Actuators
Electric motor actuators allow for manual, semi-automatic, and automatic operation. They use a reversible motor connected to a gear train to increase torque. Limit switches can be included to stop the motor automatically at fully open and fully closed positions.
Pneumatic Actuators
Pneumatic actuators translate air signals into valve stem motion, using air pressure on a diaphragm or piston. They can be programmed for various functions, such as using air pressure to open the valve and spring pressure to close it, making them fast-acting for throttle valves.
Hydraulic Actuators
Hydraulic actuators are used when significant force is needed, such as for main steam valves. They use hydraulic fluid to change pressure and move the piston, opening or closing the valve. Hydraulic actuators are available in various sizes and are economical for use in valve systems.
Thermal Actuators

 

Thermal actuators respond to changes in media temperature, opening or closing the valve to adjust to preset temperature and pressure specifications.

Material Of Construction

MaterialSize Temperature 
 inchesmmF
Butyl rubber0.6-1415-350-22 to 134-30 to 90
Nitril rubber0.6-1415-35014 to 134-10 to 90
Neoprene0.6-1415-350-4 to 134-20 to 90

Natural/synthetic

rubber

0.6-1415-350-40 to 134-40 to 90
White natural rubber0.6-515-125-31 to 134-35 to 90
White butyl0.6-615-150-22 to 212-30 to 100
Viton0.6-1415-35041 to 2845 to 140
Hypalon0.6-1415-35032 to 1340 to 90
Butyl rubber0.6-1415-350-4 to 248-20 to 120

 

Diaphragms can be made from various materials, chosen based on the type of material being handled, as well as the temperature, pressure, and frequency of operation. Elastomeric diaphragm materials are highly resistant to chemicals even at high temperatures, but their mechanical strength may weaken at temperatures above 150°F. High pressure can also damage the diaphragm.
 
This is a chart showing examples of different diaphragm materials and their specifications.
 
Diaphragm valve bodies can be made from various materials, including plastic-lined, rubber-lined, glass-lined, solid metals and alloys, or solid plastic. These valves are often more cost-effective because only the body and diaphragm need to be chemically compatible with the system media, as the other components are sealed off from the media.
 
  • Selection Tip: If the diaphragm valve will be used in a high-pressure, high-temperature system, it’s important to consult the manufacturer to confirm a safe valve design.

Connection Type

Diaphragm valves can be connected to various piping systems. The choice of connection type depends on the existing system requirements and the type of seal needed. Below are some common connection types:
 
Threaded
Threaded valve ends have internal or external threads, allowing a pipe to be screwed into or over the valve end. This is a simple and popular design for many piping systems.
Compression Fitting
Compression fittings create a seal without soldering or threading. The seal forms when a nut is tightened, compressing a washer around the pipe to create a watertight closure.
Bolt Flange
Bolt flanges are used to connect the valve to the inlet or outlet. They are secured by bolts for a sturdy connection.
Clamp Flange
Clamp flanges are spring-hinged flanges that wrap around a pipe to create a connection.
Tube Fitting
Tube fittings allow for a direct connection from a tube to the valve, making it a straightforward option for certain systems.
Butt Weld
A butt weld holds two pieces together at a joint, where the ends are butted against each other without overlapping or interlocking.
Socket Weld/Solder
Socket weld connections involve soldering two pieces together, creating a strong but permanent bond that is difficult to undo.
Metal Face Seal
Metal face seals use a metal gasket placed between two fitting parts. The gasket forms a tight seal on each side of the fitting.

"Non-wetted" and "Wetted"

Non-wetted and wetted are terms used to describe the body and stem design.

Non-wetted
Valves have the stem and body isolated from the media in the system. Therefore, the stem and body do not need to be made of a corrosive-resistant material.
Wetted
Valves leave the stem and body exposed to the media in the line. In a diaphragm valve, the body and diaphragm are the only wetted pieces of the valve, allowing for chemically compatible materials to be selected for almost any process media

Flow Coefficient

The valve flow coefficient measures how many U.S. gallons per minute of 60°F water will flow through a valve at a specific opening with a 1 psi pressure drop across the valve. This determines the appropriate valve size to achieve the desired flow rate while maintaining stable control of the process fluid. In a control valve, the flow rate changes based on the valve’s opening. There are 2 key relationships used to calculate the flow rate:
 
  • Linear: The flow rate is directly proportional to the disc’s travel. For example, if the disc is open at 50%, the flow rate is at 50% of the maximum flow.
  • Equal Percentage: The flow rate changes based on the percentage of valve opening. For instance, if opening the valve from 20% to 30% increases the flow rate by 70%, then changing it from 30% to 40% would result in another 70% increase in flow rate.
Diaphragm Valve 11

Pressure Drop

Pressure drop refers to the difference in pressure between the inlet and outlet of a valve. This is a key factor to consider when choosing the right size for a diaphragm valve. If the pressure drop across a fully opened valve is too small compared to the total system drop, there will be minimal change in fluid flow until the valve starts to close. In such situations, a fast-acting valve may be more suitable.

Rangeability

Rangeability is an important consideration when selecting a valve type. It refers to the ratio of the maximum to minimum flow rates that a valve can effectively control. This characteristic is influenced by the valve’s geometry, seat leakage, and the accuracy or stiffness of the actuator near valve closure.
 
The geometry of the valve is determined by the design of the seat and closure, which inherently affects rangeability. Excessive seat leakage can lead to instability as the valve lifts off the seat, impacting control precision. Rangeability is calculated by dividing 100% by the percentage accuracy at a low stroke, such as 5%, which would result in a rangeability of 20:1.
 
While higher rangeability allows for control over a wider range of flow rates, it is not always necessary to have the highest rangeability for most systems. For example, V-notched ball valves have a rangeability of 200:1, and globe valves have a rangeability of 100:1. Generally, higher rangeability indicates lower sensitivity when the valve is nearly closed, with sensitivity increasing as the valve opens.

Valve Sizing

Proper sizing is crucial when selecting a diaphragm valve for throttling. Since there’s no pressure drop in a simple open/close system, the inlet and outlet ports are usually the same size. The valve size is determined by the volume of media flowing through the system and the flow coefficient.
 
Several factors influence valve sizing, starting with the type of media being controlled, including its specific gravity and viscosity, which affect flow rate. Additionally, the maximum inlet pressure and temperature, along with the outlet pressure (pressure drop) at maximum load, must be considered. Lastly, the maximum capacity and the pressure drop the valve must close against, factor can be adjusted using the chart below:

Cv/d2

di/Do (inches)

    

0.5

0.6

0.7

0.8

0.9

 

4

0.99

0.99

1

1

1

6

0.98

0.99

0.99

1

1

8

0.97

0.098

0.99

0.99

1

10

0.96

0.97

0.98

0.99

1

12

0.94

0.95

0.97

0.98

1

14

0.92

0.94

0.96

0.98

0.99

16

0.9

0.92

0.95

0.97

0.99

18

0.87

0.9

0.94

0.97

0.99

20

0.85

0.89

0.92

0.96

0.99

25

0.79

0.84

0.89

0.94

0.98

30

0.73

0.79

0.85

0.91

0.97

35

0.68

0.74

0.81

0.89

0.96

40

0.63

0.69

0.77

0.86

0.95

Features and Benefits

Diaphragm Valve 12
The NTVAL Diaphragm Valve is often one of the most cost-effective solutions for chemical applications, thanks to the variety of available wetted materials. Manufacturers offer diaphragm valves with several features tailored to different applications, such as:
  • Position Indicators: Piston indicators are located on top of the valve to show the direction of flow, making it easier to monitor and control the system.
  • Adjustable travel stop
  • Protective stem cap
  • O-ring sealed stem
  • Bronze bushing
  • Position indicator
  • Molded closed diaphragms
  • PVDF corrosion-resistant coating

Applications

Diaphragm valves, with their minimal contact surfaces, are considered the cleanest valve type and are widely used in industries like pharmaceuticals, food processing, and water treatment. They are also common in the electronics, pulp and paper, power industries, and high-purity water systems.

Slurry Applications

The diaphragm valve’s streamlined flow path and lack of cavities make it ideal for slurry applications. Cavities in other valves can trap solids, increasing operational torque or inhibiting function. The NTVAL Weir Diaphragm Valve is recommended for slurries with 15% or less solids, while the NTVAL Straightway Diaphragm Valve is better suited for slurries with more than 15% solids.

High-Purity Applications

The NTVAL Diaphragm Valve is an excellent choice for high-purity applications, where minimizing particle generation and preventing product entrapment are critical.

Corrosive Applications

With a wide range of plastic linings, PTFE diaphragms, and corrosion-resistant coatings, NTVAL Diaphragm Valves offer strong protection against chemical attack and corrosion, making them suitable for corrosive applications.

Vacuum Applications

The diaphragm valve is designed for bubble-tight shut-off down to 0.1 microns. It can be equipped with either elastomer or Teflon (PTFE) diaphragms, depending on the application. The in-leakage rate for elastomer diaphragms is less than 1 x 10⁻⁶ cc-atm/sec, with even lower rates available upon request.

Standards

The Manufacturers Standardization Society (MSS) for the Valves and Fittings Industry specifies a bubble-tight shut-off standard for zero leakage.

Bubble-Tight Shut-Off

NTVAL Weir Diaphragm Valves provide bubble-tight shut-off from 0.1 microns to 200 psi, in accordance with MSS SP-88 (Standard Practice for Diaphragm Type Valves by the Manufacturers Standardization Society of the Valves and Fittings Industry, Inc.).

Broad Material Availability

With a variety of body and diaphragm materials available, the NTVAL Diaphragm Valve often offers the most economical solution for process systems.

Bonnet Isolation

The working parts of the valve are isolated from the process fluid, preventing contamination.

Secondary Containment

An optional sealed bonnet provides a secondary containment barrier in case of diaphragm failure, preventing the process media from escaping into the atmosphere.
Diaphragm Valve 13
Diaphragm Valve 14

Availability

Body Pattern
  • Weir Body
  • Straight Body
Standards Compliance
  • DIN3202
  • BS5156
  • MSS SP-88
Ends Connections
  • Flanged Ends
  • Welded Ends
  • Threaded Ends
  • Other Options Upon Request

Test Durations and Test Pressures Based on Diaphragm Maximum Service Pressure Ratings

SIZE

(in.)

Maximum Pressure

Rating psi (bar)

Shell Test Pressure

psi(bar)

Minimum Durationof

Shell Test Minutes(1)

Seat Test

Pressure psi (bar)

Minimum Duration of

Seal Test Minutes(1)

1/2-1

200(13.8)

240(16.5)

1/4

200(13.8)

1/4

1-1/2-2

175(12.1)

210(14.5)

1/4

175(12.1)

1/4

2-1/2-4

150(10.3)

180(12.4)

1

150(10.3)

1/2

5-6

125(8.6)

150(10.3)

1

125(8.6)

1/2

8

100 (6.9)

120 (8.3)

1

100(6.9)

1/2

10-12

65(4.5)

80 (5.5)

3

65(4.5)

1/2

(1)Theminimum  duration is the period of inspection after the valve is fully prepared and under full test pressure.

Body Materials Available

WEIR BODIES

  

Body Type

Material

Identification*

Maximum Temperature**

   

F

Metal

Iron

Cl or GXXX

350

107

Ductile Iron

DI or DXXX

350

177

Carbon Steel

WCBor LCB

350

177

Bronze

B61 or B62

350

177

Stainless

CF8M

350

177

Steel 316

   

CN7M

CN7M

350

177

Monel

M35

350

177

Hastelloy

CWXM

350

177

Plastic Lined

PP

Blue

200

93

PVC

Grey

140

60

Saran

Black

175

80

PVDF

White with tab

285

140

PTFE

White

300

149

Rubber Lined

Soft Natural

#5

180

82

Neoprene

#7

200

93

HypalonCSM

#9

200

93

Hard Natural

#10

200

93

Soft Gum

#11

140

60

Rubber

   

Graphite

#12

200

93

Loaded

   

Natural

   

Butyl

#16

200

93

Glass Lined

Borosilicate

Blue glass

350

177

Glass

   

STRAIGHTWAY BODIES

Body Type

Material

Identification*

Maximum Temperature**

   

F

Metal

Iron

Clor GXXX

225

107

Carbon Steel

WCB

225

107

Stainless

CF8M

225

107

Steel 316

   

Plastic lined

PP

Blue

200

93

Tefzel ETFE

White

225

107

Rubber lined

Soft Natural

#5

180

82

Neoprene

#7

200

93

HypalonCSM

#9

200

03
00

Hard Natural

#10

200

93

Butyl

#16

200

93

Glass lined

Borosilicate

Blue glass

225

107

Glass

   

*Xdesignates a numerical value

**Temperature may decrease dependent on media,pressure and valve size.

Recommended Guidelines

These guidelines are recommended to optimize performance and may vary depending on the specific media and conditions. The goal is to help prevent cavitation, choke flow, and premature wear of the lining and diaphragm.
 

WEIR VALVES

Maximum Velocity ≤25 fps for media with no suspended solids

Maximum Velocity ≤10 fps for media with 1-15% solids

Maximum Valve P ≤25% Pinlet for throttling

Maximum Solids ≤15%

 

STRAIGHTWAY VALVES

Maximum Velocity≤25 fps for media with no suspended solids

Maximum Velocity≤15 fps for media 1-15% solids

Maximum Velocity≤10 fps for media with solids>15%

Maximum Solids≤50%

Body Lining Materials Instruction

BODY LINING MATERIALS INSTRUCTION

Material

Code

Suitable  temperature

Applicable medium

*Fluorinated ethylene propylene

FEP、F46

150℃

This material can withstand different densities of hydrochloric acid, sulfuric acid, hydrofluoric acid, aqua regia, nitric acid, and various types of organic acids, alkalis, and weak acids. It is resistant to alternating exposure to strong acids and other corrosive media, except for molten alkali metals, elemental fluorine, and aromatic hydrocarbons.

Poly

chlorotrifluoroethylene

PCTFE、F3

≤120℃

Polyvinylidene fluoride

PVDF、F2

≤120℃

Ethylene tetrafluoroethylene

TFE/E、F40

≤120℃

Tefzel

 

 

Perfluoroalkoxy

PFA

≤180℃

Acid-resistant enamel

 

≤100℃

This material is generally resistant to corrosive media, except for hydrofluoric acid, strong phosphoric acid, and strong alkalis.

Reinforced

polypropylene

RPP

≤100℃

≤100℃

This material is resistant to most organic acids, mineral acids, and inorganic solvents, except for strong nitric acid, oleum, chlorosulfonic acid, and strong oxidizing agents.

Polyolefin

PO

≤100℃

The product is suitable for transporting various media, such as corrosive gases, liquids, and solid-liquid mixtures. It has excellent resistance to corrosion from acids, alkalis, and salt solutions. Additionally, it features static resistance and is non-toxic.

Castiron unlined

 

≤100℃

Non-corrosive medium

Stainless steel,unlined

 

≤150℃

Usual corrosive medium

Fluorinated ethylene

propylene

FEP

≤120℃

The material is resistant to different densities of sulfuric acid, hydrofluoric acid, aqua regia, high-temperature strong nitric acid, various organic acids, strong oxidants, alternating exposure to strong and weak acids, alternating exposure to acids and alkalis, and many types of organic solvents.

Perfluoroalkoxy

PFA

≤150℃

 

 

 

Teflon

PTFE

≤180℃

Also have the good features of corrosion

resistance, heat and electric resistance,

viscosity resistance, viscosity resistance and

low frictional coefficient.

 

 

 

Note: *Marked is NTVAL standard construction

The temperatures shown in the table are for reference only, as actual temperatures may vary depending on specific working conditions. Please consult the manufacturer for further details.

Materials Instruction

Material

Code

Suitable Temperature

Applicable Medium

Isobutylene-Isoprene Rubber

IIR

≤120°C

Except for concentrations of sulfuric acid above 75%, hydrochloric acid above 20%, hydrofluoric acid below 60%, phosphoric acid above 85%, corrosive alkalis, and esters.

Natural Rubber

NR

≤85°C

Purified water, mineral salts, and diluted mineral acids, etc.

Ethylene-Propylene-Diene Monomer (EPDM) Vistalon

EPDM

≤120°C

Acid and alkali resistance, similar to natural rubber. Suitable for applications involving low-pressure steam, hot water, and cold water.

Chloroprene Rubber

CR

≤85°C

Better acid and alkali resistance, non-polar solvent resistance, and abrasion resistance compared to natural rubber.

Nitrile Rubber (Buna-N)

NBR

≤85°C

Oil-resistant and abrasion-resistant, with the same level of acid resistance as natural rubber.

Hypalon

CSPE

≤120°C

Ozone resistance, atmospheric aging resistance, acid and alkali resistance, oxidant and chemical resistance, burning and heat resistance. Not resistant to petroleum or aromatics.

Fluoroelastomer (Viton)

FKM

≤150°C

Corrosion resistance similar to fluoroplastics. Highly stable in strong acids, strong oxidants, organic solvents, and alkali solvents.

Silicone Rubber

SI

≤200°C

Heat-resistant, excellent electrical insulation, and wear-resistant. Resists corrosion from dilute acids, alkalis, salts, and water but not from petroleum products like gasoline.

Note:

Marked as NTVAL standard construction. The temperatures shown in the above table are for reference only, as actual temperatures may vary depending on specific working conditions. Please consult the manufacturer for further details.

Cv VALUES

STRAIGHTWAY VALVE CV RATINGS (100%OPEN)

ITEM

1/2

1

1-1/2

2

2-1/2

3

4

6

8

10

12

Flanged Unlined

11

60

115

275

450

525

700

2250

4250

5000

5000

Flanged Plastic Lined

 

24

80

209

 

370

569

1400

2644**

  

Flanged Hard Rubber Lined

 

55

130

260

365

460

700

1800

3500

4850

4850

Flanged Soft Rubber Lined

 

42

79

220

365

460

700

1800

3500

4850

4850

Flanged Glass Lined

 

48

100

270

425

475

700

1950

4400

  

Screwed End

15

39

120

265

       

Note: Flanged Soft Rubber=soft natural rubber,Neoprene,Hypalon and Butyl linings

        Flanged HardRubber = hard natural rubber lining.

Note: Data is based on estimates.

 

Cv VALUES

STRAIGHTWAY VALVE CV RATINGS (100%OPEN)

ITEM

1/2

3/4

1

1-1/4

1-1/2

2

2-1/2

3

4

6

8

10

12

Flanged Unlined

5.5

22

22

56

56

70

160

190

310

600

1200

1800

2550

Flanged Plastic Lined

10

10

38

38

67

100

175

285

690

1070

Flanged Hard Rubber Lined

4.0

10

10

31

31

55

115

160

260

625

1150

1750

2350

Flanged Soft Rubber Lined

2.0

7.0

7.0

25

25

50

110

155

250

515

1150

1750

2350

Flanged Glass Lined

5.5

22

22

53

53

78

180

250

420

850

1700

Screwed End

4.4

10

19

48

48

70

95

172

Butt Weld

3.5

7.5

18.6

 

48

70

95

180

400

600*

1200*

Note:*Data is based on estimates

           
Diaphragm Valve 15

Instruction of Diaphragm Valve Face to Face Available

The length of valve body structure and the dimension of flange connection can be manufactured according to the following table or according to the requirements of customers.
Diaphragm Valve 16
Diaphragm Valve 17

Materials

PARTS

Item

Description

Material

1

Body Flanged

Cast Iron

2

Bonnet

Cast Iron

3

Compressor

Cast iron

4

Diaphragm

Elastomer

5

Bushing

Brass

6

Handwheel

Cast Iron

7

Spindle

Steel

8

Spindle, Extension (indicating)

Stainless Steel

9

Insert

Steel

10

Spacer

Steel

11

Pin, Spirol

Stainless Steel

12

Washer,Shim

Polyethylene

13

Bearing, ThrustNeedle

Steel

14

Bearing, Thrust Race

Steel

15

Screw, SetHex. Soc.

Steel

16

Fitting, Tube

Steel

17

Screw, Hex,Ho, Cp

Steel

18

Nut, Hex.

Steel

19

Pin, Spirol

Stainless Steel

20

Capseal

Brass

Weir Pattern Diaphragm Valve

  • Body Options: Weir pattern available with either unlined or fully lined body.
  • Compressor Coating: Elastomer or PTFE-coated compressor.
  • Coating: Epoxy coating applied both inside and outside for added protection.
  • Shut-off and Containment: Provides bubble-tight shut-off with secondary containment.
  • Design Standard: Designed according to BS5156 standards.

Specification

Standard

Face to Face

BS5156

End Flange

BS4504

Ratings

PN10/16

Diaphragm Valve 18

SIZE(DN)

Nominal pressure

MPa

Working pressure

MPa

L

D

D1

n-Φd

f

H1

H2

D0

W.T(kg)

        

Unit:mm

15

1.6

1.6

108

95

65

4-14

2

90

99

66

2

20

  

117

105

75

4-14

2

93

103

66

3

25

  

127

115

85

4-14

2

100

112

66

4

32

  

146

140

100

4-18

2

127

144

96

6.5

40

  

159

150

110

4-18

2

136

156

96

7.5

50

  

190

165

125

4-18

2

151

177

118

10

65

1

1

216

185

145

4-18

2

183

213

165

16

80

  

254

200

160

8-18

2

198

273

230

23.5

100

  

305

220

180

8-18

2

266

320

280

34

125

  

356

250

210

8-18

3

319

386

280

44

150

  

406

285

240

8-22

3

380

453

368

67.5

200

1

0.6

521

340

295

8-22

3

506

626

400

141.5

250

  

635

395

350

12-22

5

598

734

500

229

300

1

0.4

749

445

400

12-22

5

698

778

560

321

350

  

787

5105

460

16-22

5

723

883

560

360

400

1

0.25

914

565

515

16-26

5

868

1078

640

584

Pneumatic Fail Closed Diaphragm Valve

  • Valve Pattern: Weir Pattern, Pneumatic Fail Closed
  • Body Options: Available in unlined or fully lined body
  • Compressor Coating: Elastomer or PTFE-coated compressor
  • Coating: Epoxy coating applied both internally and externally
  • Shut-off and Containment: Bubble-tight shut-off with secondary containment
  • Design Standard: Designed according to BS5156

Specification

Standard

Face to Face

BS5156

End Flange

BS4504

Ratings

PN10/16

Diaphragm Valve 19

SIZE

(DN)

Nominal pressure

MPa

Working pressure

MPa

L

D

D1

n-Φd

f

H

     

Unit:mm

15

1.6

1.6

108

95

65

4-13.5

2

 

20

  

117

105

75

4-13.5

2

 

25

  

127

115

85

4-17.5

2

394

32

  

146

140

100

4-17.5

2

400

40

  

159

150

110

4-17.5

2

485

50

  

190

165

125

4-17.5

2

635

65

1.0

1.0

216

185

145

8-17.5

2

650

80

  

254

200

160

8-17.5

2

660

100

  

305

220

180

8-17.5

2

816

125

 

0.6

356

250

210

8-22

3

825

150

  

406

285

240

8-22

3

1013

200

 

0.4

521

340

295

 

3

1300

SIZE

(DN)

D0

B

Code ES

Air pressure Mpa

Air joint in

Air consumption cm3

W.T(kg)

Unit:mm

15

       

20

120

168

61

0.3

1/8

163.89

7.2

25

120

168

61

0.3~0.4

1/8

196.65

8.9

32

120

168

61

0.3~0.4

1/8

229.4

10.6

40

165

260

62

0.3~0.4

1/4

1425.7

19.5

50

165

318

63

0.3~0.4

1/4

2284.1

34.9

65

165

318

63

0.3~0.4

1/4

3048

39.9

80

165

318

63

0.4~0.5

1/4

3244.7

51.9

100

280

425

64

0.4~0.5

3/8

6964.5

93.2

125

280

425

64

0.4~0.5

3/8

7439.7

105.3

150

310

549

65

0.5

3/8

14912

184.5

200

483

749

66

0.6

1/2

49161

407.4

 

Pneumatic Fail Opened The Diaphragm Valve

  • Valve Pattern: Weir Pattern, Pneumatic Fail Opened
  • Body Options: Available in unlined or fully lined body
  • Compressor Coating: Elastomer or PTFE-coated compressor
  • Coating: Epoxy coating applied both internally and externally
  • Shut-off and Containment: Bubble-tight shut-off with secondary containment
  • Design Standard: Designed according to BS5156

Specification

Standard

Face to Face

BS5156

End Flange

BS4504

Ratings

PN10/16

Diaphragm Valve 20

SIZE

(DN)

Nominal pressure

MPa

Working pressure

MPa

L

D

D1

n-Φd

f

H

     

Unit: mm

15

1.6

1.6

108

95

65

4-13.5

2

343

20

  

117

105

75

4-13.5

2

345

25

  

127

115

85

4-17.5

2

363

32

  

146

140

100

4-17.5

2

430

40

  

159

150

110

4-17.5

2

575

50

  

190

165

125

4-17.5

2

588

65

1.0

1

216

185

145

8-17.5

2

769

80

  

254

200

160

8-17.5

2

816

100

  

305

220

180

8-17.5

2

820

125

1.0

0.6

356

250

210

8-22

3

920

150

  

406

285

240

8-22

3

1010

200

1.0

0.4

521

340

295

12-22

3

 

250

  

635

395

350

 

5

 

SIZE

(DN)

D0

B

Code ES

Air pressure Mpa

Air joint in

Air consumption cm3

W.T (kg) Unit:mm

15

       

20

140

168

68

0.3

1/8

163.87

6.3

25

140

168

68

0.3~0.4

1/8

196.65

7.3

32

140

260

68

0.3~0.4

1/8

229.4

8.3

40

140

260

69

0.3~0.4

1/4

1458.7

14.3

50

140

260

70

0.3~0.4

1/4

3162.7

26

65

140

260

70

0.3~0.4

1/4

3243

30.8

80

165

425

71

0.4~0.5

3/8

6636.8

64.9

100

280

425

71

0.4~0.5

3/8

6948

70.3

125

280

425

71

0.4~0.5

3/8

7374.2

80.7

150

280

549

72

0.5

3/8

10652

131.2

200

280

549

72

0.6

3/8

16715

212

250

       

Pneumatic Reciprocal Diaphragm Valve with Manual

  •  Valve Pattern: Weir Pattern, Pneumatic Reciprocal Type
  • Body Options: Available in unlined or fully lined body
  • Compressor Coating: Elastomer or PTFE-coated compressor
  • Coating: Epoxy coating applied both internally and externally
  • Shut-off and Containment: Bubble-tight shut-off with secondary containment
  • Design Standard: Designed according to BS5156

Specification

Standard

Face to Face

BS5156

End Flange

BS4504

Ratings

PN10/16

Diaphragm Valve 21

SIZE

(DN)

Nominal pressure 

MPa

Working pressure

MPa

L

D

D1

n-Φd

f

H

     

Unit: mm

15

1.6

1.6

108

95

65

 

2

 

20

  

117

105

75

4-13.5

2

343

25

  

127

115

85

4-13.5

2

345

32

  

146

140

100

4-17.5

2

363

40

  

159

150

110

4-17.5

2

430

50

  

190

165

125

4-17.5

2

575

65

1

1

216

185

145

4-17.5

2

588

80

  

254

200

160

8-17.5

2

769

100

  

305

220

180

8-17.5

2

816

125

  

356

250

210

8-17.5

3

820

150

  

406

285

240

8-22

3

920

200

1

0.6

521

340

295

8-22

3

1010

250

  

635

395

350

 

5

 

SIZE

(DN)

D0

B

Code ES

Air pressure

(Mpa)

Air joint

in

Air consumption 

(cm3)

W.T(kg) Unit:

(mm)

15

       

20

140

168

54

0.3

1/8

163.87

5.6

25

140

168

54

0.3~0.4

1/8

196.65

6.8

32

140

260

55

0.3~0.4

1/8

229.4

7.7

40

140

260

55

0.3~0.4

1/4

1458.7

13.9

50

140

260

55

0.3~0.4

1/4

3162.7

24.5

65

140

260

55

0.3~0.4

1/4

3243

29

80

165

425

56

0.4~0.5

3/8

6636.8

63

100

280

425

57

0.4~0.5

3/8

6948

66

125

280

425

57

0.4~0.5

3/8

7374.2

75

150

280

549

58

0.5

3/8

10652

125

200

280

549

58

0.6

3/8

16715

206

250

       

Straight Through Diaphragm Valve

  • Valve Pattern: Straight Through
  • Body Options: Available in unlined or fully lined body
  • Compressor Coating: Elastomer or PTFE-coated compressor
  • Coating: Epoxy coating applied both internally and externally
  • Shut-off and Containment: Bubble-tight shut-off with secondary containment
  • Design Standard: Designed according to BS5156

 

Specification

Standard

Face to Face

BS5156

End Flange

BS4504

Ratings

PN10/16

Diaphragm Valve 22

SIZE

(DN)

Nominal pressure

MPa

Working pressure

MPa

L

D

D1

n-Φd

f

H1

H2

D0

W.T (kg)

        

Unit: mm

20

1.0

1.0

117

105

75

4-14

2

150

162

  

25

  

127

115

85

4-14

2

150

162

120

3.5

32

  

146

140

100

4-18

2

152

180

120

5

40

  

159

150

110

4-18

2

152

180

120

6

50

  

190

165

125

4-18

2

163

198

120

8.5

65

  

216

185

145

4-18

2

205

227

230

16

80

  

254

200

160

8-18

2

220

252

230

22

100

  

305

220

180

8-18

2

262

300

280

32

125

1

0.6

356

250

210

8-18

3

290

335

280

43.5

150

  

406

285

240

8-22

3

368

427

368

65

200

  

521

340

295

8-22

3

410

470

483

112.5

250

1

0.4

635

395

350

12-22

5

479

569

483

192.5

300

  

749

445

400

12-22

5

550

650

660

296

350

  

787

505

460

16-22

5

550

650

560

 

400

1

0.25

914

565

515

16-26

5

  

640

 

Vacuum Diaphragm Valve

  • Valve Pattern: Straight Through
  • Connection Types: Available with threaded or weld ends
  • Shut-off: Bubble-tight shut-off
  • Design Standard: Designed according to BS5156

 

Specification

Standard

Face to Face

VATAC Standard

Flanged End

BS4504

Lap Joints Ends

VATAC Standard

Ratings

PN10

Diaphragm Valve 23
CONNECTING PIPE WELDED END FIGURE 1

Model

DN

D

H

A

L

L1

     

Unit: mm

GM-10C-H(I)

10

19

80

55

240

120

GM-25C-H(I)

25

32

105

80

240

120

GM-40C-H

40

45

133

100

240

120

GM-50C-H

50

57

157

100

240

120

GM-10D-H(I)

10

19

77.5

50

150

150

GM-25D-H(I)

25

32

105

60

75

75

CONNECTING PIPE WELDED END FIGURE 2

Model

DN

D

H

A

L

L1

     

Unit: mm

GM-10C-H(Ⅱ)

10

19

80

55

195

120

GM-25C-H(Ⅱ)

25

32

105

80

236

120

GM-10D-H(Ⅱ)

10

19

77.5

50

150

75

GM-25D-H(Ⅱ)

25

32

105

66

175

75

QUICK UNLOAD FLANGED END FIGURE 3

Model

DN

D

D1

H

A

L

     

Unit: mm

GM-10C-KF

10

30

12.2

80

55

75

GM-25C-KF

25

40

26.2

105

80

120

GM-10C-KF

40

50

41.2

133

100

120

LAP JOINT FLANGED END FIGURE 4

Model

DN

D

D1

H

A

L

n-Φc

      

Unit:mm

GM-10C

10

46

36

80

55

75

4-Φ6

GM-25C

0

70

55

105

80

120

4-Φ7

GM-40C

40

100

80

133

100

150

4-Φ9

GM-50C

50

110

90

157

100

180

4-Φ9

Sanitary Diaphragm Valve

  • Valve Pattern: Straight Through
  • Connection Types: Available with threaded or weld ends
  • Shut-off: Bubble-tight shut-off
  • Design Standard: Designed according to BS5156

Specification

Standard

Face to Face

VATAC Standard

Flanged End

BS4504

Ratings

PN10

Diaphragm Valve 24

SIZE(DN)

A

B

E

F

       

Unit: mm

15

108

34

80

89/99

20

118

50.5

80

91/102

25

127

50.5

80

110/123

32

146

50.5

80

129/138

40

159

50.5

120

139/159

50

191

64

120

159/186

Threaded Diaphragm Valve

  • Valve Pattern: Weir Pattern
  • Connection Types: Female Threaded Ends
  • Shut-off: Bubble-tight shut-off
  • Design Standard: Designed according to BS5156

Specification

Standard

Face to Face

VATAC Standard

End Flanged

BS4504

Threaded Ends

BS EN10241

Ratings

PN10/16

Diaphragm Valve 25

SIZE

(DN)

Nominal

pressure

Working

pressure

MPa

L

SW

b

H1

H2

D0

W.T

(kg)


Unit:mm

8

1.6

1.6

50

20

 

60

66

45

0.6

10

  

50

24

   

45

0.7

15

  

65

38

8

84

92

50

0.8

20

  

85

40

12

93

103

50

1.1

25

  

110

48

18

106

120

66

1.9

32

  

120

58

18

137

156

96

3.3

40

  

140

69

18

142

163

96

4.2

50

  

165

82

20

167

192

96

5.8

65

1.6

1

203

90

30

190

225

165

9.5

Pinch Valve

  • Flow Pattern: Straight Through Flow
  • Cover and Ends: Bolted cover with flanged ends
  • Body Lining: Fully body elastomer rubber lined
  • Design Standard: Designed to ISO Standard

Specification

Standard

Face to Face

VATAC Standard

Threaded Ends

EN Standard

Ratings

PN6/10/16

Diaphragm Valve 26
Manual

DN

Nominal

pressure

Mpa

Working

pressure

MPa

L

L1

L0

D

 

n –

Φd

D0

H

W.T

(kg)

Unit:

mm

25

0.6

0.6

160

124

31

115

85

4-14

120

137

3

32

   

165

145

40

140

100

4-18

140

174

4.5

40

   

190

157

50

150

110

4-18

140

186

5.5

50

   

210

160

60

160

125

4-18

16

205

7.5

u

   

270

199

74

180

145

4-18

160

238

10.5

80

   

300

222

88

195

160

4-18

200

241

15.5

100

   

350

250

106

215

180

8-18

240

301

20

125

   

430

318

134

245

210

8-18

280

3bU

32.5

150

   

500

350

158

280

240

8-23

320

348

48

200

0.6

0.4

650

446

206

335

295

8-23

560

430

85

250

   

800

516

256

395

350

12-23

560

540

 

300

   

950

562

304

445

400

12-23

620

741

 

350

   

1100

   

500

460

16-23

     
Electric

DN

H

A

B

D0

Kw

W.T

(kg)

      

Unit:

mm

25

 

443

133

 

0.12

3

32

     

4.5

40

     

5.5

50

 

552

425

305

0.25

7.5

65

 

552

425

305

0.37

10.5

80

 

552

425

305

0.75

15.5

100

 

552

425

305

0.75

20

125

     

32.5

150

1000

    

48

200

1174

766

390

305

1.1

102

250

      

300

      

350

      

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Additional General Insights Here

Specs of Diaphragm Valve

Body Materials

The body material of a Diaphragm Valve, such as stainless steel, carbon steel, and ductile iron, affects its performance. Stainless steel resists corrosion, carbon steel provides strength for high-pressure applications, and ductile iron is tough and wear-resistant. NTVAL’s Diaphragm Valves use these materials for durability and reliability in demanding conditions.

Diaphragm Materials

The diaphragm can be made from materials like EPDM and PTFE. PTFE, with corrosion-resistant coatings, offers excellent protection against chemical attack and corrosion. EPDM resists heat, water, and steam, making it ideal for industrial use. Now get this: EPDM’s design provides durability and reliable performance in tough environments.

Valve Size

Diaphragm Valves in industrial settings are often large, capable of handling significant flow rates and enduring high-pressure applications. These valves can range up to 12 inches in size, which allows them to manage substantial volumes of fluids and maintain system efficiency under demanding conditions.

Features of Diaphragm Valve

Leak-Proof Design

One of the standout features of Diaphragm Valves is their leak-proof design. The flexible diaphragm creates a tight seal, preventing leaks even in high-pressure systems. Using the leak-proof design of such valves in the chemical industry avoids hazardous spills. NTVAL large industrial valves guarantees safety and reliability in demanding environments, providing dependable operation in critical applications.

Precise Flow Control

Diaphragm Valves offer precise control over fluid flow, which is essential for effective fluid dynamics and maintaining operational efficiency. Their design provides a tight seal to prevent leakage, enhancing system safety and reliability. Additionally, these valves minimize turbulence and pressure drop, leading to improved overall system performance.

Low Friction Operation

Diaphragm Valves feature a low frictional coefficient, which reduces wear and tear on internal components. This not only extends the valve’s lifespan but also maintains consistent performance and reduces maintenance needs. The low friction design supports smooth operation, which is essential for accurate fluid control and reliable performance in demanding industrial applications.

Benefits of Diaphragm Valve

Enhanced Safety

Diaphragm Valves enhance safety in industrial environments by providing a reliable seal that prevents leaks and contamination. This is especially important in industries handling hazardous or toxic substances. Valve safety is crucial because a reliable seal can prevent accidents and protect workers, which is essential for maintaining a safe workplace.

Reduced Maintenance Costs

Using Diaphragm Valves can reduce maintenance costs due to their simple design and ease of maintenance. The high-quality sealing performance minimizes wear and tear, extending the lifespan of the valves. These valves lower operational costs with minimal part replacements and maintenance, and their durability with corrosive and high-temperature fluids makes them cost-effective for long-term industrial use.

Versatility in Applications

Diaphragm Valves are highly versatile, making them suitable for a wide range of applications. They can handle different types of fluids and operating conditions, from high temperatures to corrosive environments. It turns out, this versatility makes them an excellent choice for large-scale industrial operations, where different processes require different handling characteristics.

Applications of Diaphragm Valve

Petrochemical Industry

Diaphragm Valves are extensively used in the petrochemical industry for handling corrosive fluids. They are essential in processes involving aggressive chemicals, which can quickly wear down less durable materials. These valves provide safe and efficient flow control in various stages of petrochemical production. NTVAL’s high-quality industrial valves are particularly effective in these applications.

Mining and Steam & Boiling Systems

Diaphragm Valves are essential in mining for handling slurry and corrosive chemicals. They provide precise control and fluid isolation for safe and efficient operation. In steam and boiling systems, these valves regulate steam and hot water flow, performing reliably under high temperatures. Their ability to withstand thermal stress and maintain tight seals makes them vital in these applications.

Oil, Gas & Nuclear

In the oil, gas, and nuclear sectors, Diaphragm Valves are utilized for their reliability and safety features. They are used in systems handling high-pressure and high-temperature fluids. In nuclear power plants, these valves are crucial for controlling radioactive fluids and gases, providing containment and preventing leaks. Now this is important: their design minimizes the risk of failure in critical applications.

Pharmaceutical and Biotech Industries

In pharmaceutical and biotech industries, Diaphragm Valves are critical for handling sterile and sensitive fluids used in drug manufacturing and research processes. Their smooth, crevice-free design helps prevent contamination, supporting strict hygiene standards required in these environments.
Diaphragm Valve 27
Diaphragm Valve 28

4 Considerations When Buying x

01

Fluid Compatibility

The material of both the valve body and the diaphragm must be compatible with the fluid it will handle. This compatibility guarantees durability and prevents corrosion or damage from aggressive substances. Choosing the appropriate materials extends the lifespan of the valve and enhances its overall performance and reliability in industrial applications.

02

High Pressure Resistant

Diaphragm Valves need to match the pressure and temperature requirements of the application. For instance, the maximum pressure rating of many Diaphragm Valves is up to 200 psi (13.8 bar). Matching that the valve’s specifications align with system conditions helps prevent operational issues and extends the valve’s lifespan.

03

Simple Diaphragm Replacement

When choosing a Diaphragm Valve, prioritize models that allow for easy diaphragm replacement. Valves designed for simple diaphragm changes minimize downtime and operational costs by avoiding the need for complete valve disassembly. Now get this, choosing these designs simplifies the replacement process, which boosts operational efficiency and minimize maintenance interruptions.

04

ISO9001 Certified

Certifications are crucial when selecting a Diaphragm Valve, as they confirm adherence to industry standards for safety and performance. These certifications show the valves are tested and approved for demanding industrial applications. NTVAL’s high-quality valves are certified by ISO9001, demonstrating our reliability and adherence to rigorous standards.

Types of Diaphragm Valve

Wire Type Diaphragm Valve
The Weir Type Diaphragm Valve features a saddle-shaped weir that the diaphragm presses against to close the valve. Ideal for handling slurries and viscous fluids, NTVAL’s large valves prevents clogging and provides better control. For example, in chemical processing, this valve type efficiently handles abrasive fluids, allowing for smooth operation and minimal maintenance.
Pneumatic Diaphragm Valve
Pneumatic Diaphragm Valves use compressed air to control fluid flow precisely. This makes them great for automated systems in large industrial plants, improving efficiency. The fact is, these valves are perfect for places where manual operation is difficult, as they perform consistently and reduce human error.
Rubber Lined Diaphragm Valve
Rubber Lined Diaphragm Valves have an internal lining that protects against corrosive and abrasive substances. This rubber lining extends the valve’s life by preventing wear from harsh chemicals and provides a tight seal, reducing leaks. These valves are essential for maintaining system integrity in demanding industrial conditions.

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