Pulse valve diaphragms
The cheapest part in the baghouse and the one most likely to be sitting in a drawer as a spare. We supply compatible replacement diaphragms for the four valve families we are asked about most, in three elastomers, from 3/4" to 3".
Which valves these fit
Identify by valve family and port size first. If the model number is worn off, measure the old diaphragm: outer diameter, bolt circle and centre hole are enough for us to match it.
| Valve family | Typical models | Port sizes | Diaphragm type | Common spares |
|---|---|---|---|---|
| Goyen type | CA / RCA series, T series | 3/4" – 3" | Single or double | Diaphragm, spring, solenoid pilot |
| SBFEC type | DMF / DCF series, submerged and remote | 1" – 2.5" | Single or double | Diaphragm kit, armature, coil |
| ASCO / Numatics type | 353 series, 8353 type pilots | 3/4" – 2" | Single | Diaphragm, O-ring set |
| Mecair type | DB / VNP series | 1" – 3" | Double | Diaphragm kit, pilot |
Compatible replacement parts, not original equipment. Brand names are trademarks of their owners and are used only to describe fitment.
Elastomer choice decides diaphragm life
Most premature diaphragm failures we see are a material problem, not a manufacturing problem. Pick by gas temperature and chemistry, then by price.
| Material | Temperature | Good against | Avoid when | Typical use |
|---|---|---|---|---|
| NBR (nitrile) | −20 to 80 °C | Oils, general air, abrasion | Hot gas, strong acids, ozone | Standard duty, room-temperature dust collectors |
| Viton / FKM | −10 to 200 °C | Acids, hydrocarbons, heat | Steam, hot water, ketones | Incinerator and boiler baghouses, hot flue gas |
| EPDM | −40 to 120 °C | Steam, water, ozone, alkalis | Mineral oils, solvents | Wet scrubber outlets, humid gas |
| Silicone | −50 to 180 °C | Low temperature flexibility | Oils, abrasion | Cold climate installations |
Before you blame the diaphragm
A diaphragm that splits after three months is usually a symptom. In order of how often we see them:
- Water or oil in the air line. The diaphragm flexes against liquid instead of air. Check the filter regulator and drain the header.
- Over-pressure. Running above the valve rating stretches the seat area until it tears at the bolt holes.
- Wrong elastomer. NBR in a hot incinerator baghouse hardens and cracks within weeks.
- Pulse frequency too high. Short off-times mean the diaphragm never completes a full stroke.
- A worn seat or spring. A new diaphragm on a grooved seat fails again quickly.
Send a photo of the failed part and we will usually tell you which of the five it is.
Spare kit contents
- Diaphragm (single or double, per valve type)
- Diaphragm spring where used
- O-rings and gaskets for the cover
- Fixing screws on request
- Packed in individual bags, labelled with valve model
Ordering for a plant? A mixed spare kit covering each valve size on site is usually cheaper than air-freighting one diaphragm later.
Frequently asked
- Can you identify the diaphragm from a photo?
- Usually yes, if the photo is flat with a ruler or a coin for scale and shows the bolt holes. The valve model number is faster if it is still legible.
- Do you sell complete valves as well as diaphragms?
- Yes — pulse valves including submerged and remote pilot types, though most repeat business is diaphragms and pilot coils.
- How many should I keep as spares?
- A working rule is one spare set per ten valves, plus one per valve size on critical service. Diaphragms do not expire quickly if stored away from heat and sunlight.
- Are these genuine Goyen parts?
- No. They are compatible replacements made to the same dimensions and elastomer specification, offered at a lower price. If your maintenance procedure requires original parts, we will say so rather than substitute quietly.
Send the valve model, get a match
Goyen, SBFEC, ASCO, Mecair — model number and port size are all we need to quote. Mixed spare kits available.