High Pressure Diaphragm Valves
High pressure specialty gas service demands a valve that seals reliably at 3000-4500 PSI without introducing contamination. Valonix high pressure diaphragm valves use a reinforced seat and a thicker diaphragm stack so the shut-off element stays stable across the full pressure range.
Typical installations include cylinder cabinet isolation, tube trailer front and rear compartments, high pressure hydrogen and helium headers, and charging lines feeding a two-stage pressure regulator. Every valve is helium leak tested at working pressure before release.
Pressure ratings and actuation limits
Manual versions are rated up to 4500 PSI on 1/4 in bodies and 3500 PSI on 1/2 in bodies. Pneumatic versions are typically rated 3000 PSI because actuator thrust, not the diaphragm, becomes the limiting factor. Always compare the actuator rating with the body rating when specifying a normally closed valve.
- Manual: up to 4500 PSI (1/4 in) / 3500 PSI (1/2 in)
- Pneumatic: up to 3000 PSI with 60-90 PSI instrument air
- Actuator supply: 60-90 PSI clean dry air or nitrogen
Seat design for high differential pressure
At high inlet pressure the seat sees a large closing force. A resilient seat insert keeps leakage low across thermal cycling while a metal diaphragm prevents any elastomer from sitting in the main flow path. This combination keeps the valve tight at both high pressure and near-vacuum during pump-down.
- Reinforced diaphragm stack
- Low-leak seat across seat and to atmosphere
- Stable operation during vacuum purge cycles
Where high pressure valves are used
Tube trailers, cylinder filling manifolds and high pressure buffer lines use 20 MPa class valves with butt-weld ends. Semiconductor bulk gas yards use 1/4 in VCR versions at the cylinder connection, followed by a regulator before distribution to the tool.
- Tube trailer and cylinder cabinet isolation
- High pressure hydrogen and helium supply
- Bulk gas yard header shut-off
Valves in this category
VX4H-HPVX4H High Pressure Diaphragm Valve
- Port size1/4
- Max. pressure4500 PSI
- Cv0.20
VX8H-HPVX8H High Pressure Diaphragm Valve
- Port size1/2
- Max. pressure3500 PSI
- Cv0.80
CV20LCV20L High Pressure Pneumatic Valve
- Port size3/8, 1/2, 3/4
- Max. pressure20 MPa
- CvOn request
CV20ACV20A Pneumatic Cylinder Valve
- Port size3/4
- Max. pressure20 MPa
- CvOn request
Typical specifications
| Pressure class | 3000-4500 PSI / 20 MPa line valves |
|---|---|
| Port sizes | 1/4", 1/2", 3/8", 3/4" |
| End connections | VCR, butt weld, 3/4 NGT |
| Actuation | Manual or pneumatic normally closed |
| Body | 316L stainless steel |
| Test | Helium leak and hydrostatic proof |
Frequently Asked Questions
Why is the pneumatic valve rated lower than the manual valve?
The pneumatic actuator has a finite closing force. Above roughly 3000 PSI the seat load can exceed what the actuator can hold, so the assembly is derated.
Can these valves be used on hydrogen service?
Yes, with the correct material and seat selection. Hydrogen requires tight leak performance and compatible elastomers; state the gas when requesting a quote.
Do you offer 20 MPa valves for tube trailers?
Yes. The VP and CV20 families are built for 20 MPa tube trailer and high pressure pipeline duty with butt-weld ends.