Valves - diaphragms

Viton diaphragms


Viton® diaphragms

Viton® is a class of fluoropolymer elastomer (synthetic rubber) and is well known for its excellent heat, acid and chemical resistance. The performance of fluoroelastomers in aggressive chemicals depends on the grade of the elastomer.

There are three grades of Viton we currently use for our viton diaphragms:

  • Viton A the most commonly used version of Viton, but should not be used with most ketones, esters or extended steam exposure.
  • Viton A (SR) Steam resistant version of Viton A, performs well in conditions with extended steam
  • Viton GF is more chemically resistant than Viton A and offers good steam resistance. However, it should not be used with most ketones and esters.

Features and benefits

  • All Viton® diaphragms are laser-etched with cure dates and batch numbers, ensuring that they are completely traceable
  • Excellent chemical resistance
  • Not suitable for use with ketones and esters

Technical summary

Diaphragm variant(s)Bellows, Straight 
Compatible actuatorsAJS, AKS 
Compatible valvesRadial 
Material specificationFluoropolymer elastomer, Peroxide cured F-type gum polymers, Steam resistant Viton A 
StandardsASME BPE, RoHS 

Technical Summary table lists features available within the range. See ‘Specifications’ tab for model specific information.



Flow Coefficient (under standard configuration)
Tank Valve Size CV KV
0.5" 4.3 5.0
1.0" 15.8 18.3
2.0" 72.0 83.2
3.0" 170.0 196.5


Flow Coefficient (under standard configuration)
Tank Valve Size CV KV
0.5" 4.3 5.0
1.0" 15.8 18.3
2.0" 72.0 83.2
3.0" 170.0 196.5


Flow Coefficient (under standard configuration)
Tank Valve Size CV KV
0.5" 4.3 5.0
1.0" 15.8 18.3
1.5" 48.0 55.5
2.0" 72.0 83.2
3.0" 170.0 196.5


Technical specifications

Viton A diaphragmsViton A (SR) diaphragmsViton GF diaphragms
Tank valve sizes0.5", 0.5" Extended, 1.0", 2.0" 0.5", 1.0", 2.0", 3.0" 0.5" Extended, 1.0", 1.5" Extended, 2.0", 3.0", 3.0" Extended 
ColourCream Black Black 
Diaphragm variant(s)Bellows, Straight Bellows, Straight Straight 
Parylene treatmentNo No No 
Operating temperature range -20 °C to 177 °C-20 °C to 177 °C-20 °C to 177 °C
Operating temperature range -4 °F to 350 °F-4 °F to 350 °F-4 °F to 350 °F
Max. operating pressure4.8 barg4.8 barg4.8 barg
Max. operating pressure70 psig70 psig70 psig
Compatible actuatorsAJS, AKS AJS, AKS AJS, AKS 
Compatible valvesRadial Radial Radial 
Actuator typeManual, Pneumatic Manual, Pneumatic Manual, Pneumatic 
Curing agentBPA BPA Peroxide 
Steaming required prior to installationNo No No 
ASME BPE appendix K SIP cycle rating200 200 
Total actuations during SIP cycle testing2000 2000 
Shelf life4 years4 years4 years
Material specificationFluoropolymer elastomer Steam resistant Viton A Peroxide cured F-type gum polymers 
Certification and complianceADCF, BSE/TSE free, FDA 21CFR177.2600, USP <87>, USP <88> Class VI ADCF, BSE/TSE free, FDA 21CFR177.2600, USP <87>, USP <88> Class VI ADCF, BSE/TSE free, FDA 21CFR177.2600, USP <87>, USP <88> Class VI 

Materials of construction

DiaphragmSynthetic rubber compound, Viton® A Cream Fluoropolymer Elastimer, Viton® A Steam Grade 42563, Viton® GF 17340
Inserts304 SS



  1. ASEPCO weirless radial diaphragm valves (US).pdf
    PDF - 605.5kb


  1. ASEPCO diaphragms datasheet (EN).pdf
    PDF - 234.5kb

Order Information

Product codes

Viton A diaphragms product codes

Code Product


Radial diaphragm extended .5" Viton A Cream


Radial diaphragm .5" Viton A Cream Straight


Radial diaphragm 1" Viton A Cream Bellows


Radial diaphragm 2" Viton A Cream Bellows


Radial diaphragm 3" Viton A Cream Bellows

Viton A (SR) diaphragms product codes

Code Product


Radial diaphragm .5" Viton "A" - steam grade Black Straight


Radial diaphragm 1" Viton "A" - steam grade Black Straight


Radial diaphragm 2" Viton "A" - steam grade Black USP Straight


Radial diaphragm 3" Viton "A" - steam grade Black Straight

Viton GF diaphragms product codes

Code Product


Radial diaphragm 1" Viton "GF" Black Straight


Radial diaphragm 2" Viton "GF" Black Straight


Radial diaphragm 3" Viton "GF" Black Straight


Radial diaphragm extended 1.5" Viton "GF" Black


Radial diaphragm extended 3" Viton "GF" Black


Radial diaphragm extended .5" Viton "GF" Black

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