Pressure Seal Gate Valve
gate · pressure seal bonnet
- Body
- A105, A182 F11, F22, F91, F92
- Size
- NPS 2-24 (DN 50-600)
- Class
- Class 600 - 4500
- Temp
- up to 650 °C / 1200 °F
- End
- BW, SW, RTJ, RF
- Standard
- ASME B16.34
Power plant valve manufacturer / China
High-temperature and high-pressure valves
Pressure seal and integral forged gate, globe, check and stop-check valves for steam, feedwater and process service, with a document package an inspector can work through.
- Size
- NPS 2 - 36
- Class
- 600 - 4500
- Temperature
- to 650 °C
- Design code
- ASME B16.34
Catalogue range. The rating that applies to your item is set by its material and class in the ASME B16.34 table, not by the maximum shown here.
What we do, and what we do not. This is a high-temperature, high-pressure
range: steam, feedwater and severe process service, in cast and forged construction. We do
not supply cooling water, compressed air, general utility or control valves, and we will say
so rather than quote them. If your enquiry falls outside that envelope we would rather tell
you at the enquiry stage than at delivery.
Selected by system, not by catalogue number
Main steam needs creep-grade material. Feedwater takes its pressure class from the pump curve. Extraction is designed for the trip, not for normal running. Four different engineering problems, one factory.
Pressure Seal Globe Valve
globe · pressure seal bonnet
- Body
- A105, A182 F11, F22, F91, F92
- Size
- NPS 2-16 (DN 50-400)
- Class
- Class 900 - 4500
- Temp
- up to 650 °C / 1200 °F
- End
- BW, SW, RTJ, RF
- Standard
- ASME B16.34
Pressure Seal Check Valve
check · pressure seal bonnet
- Body
- A105, A182 F11, F22, F91, F92
- Size
- NPS 2-24 (DN 50-600)
- Class
- Class 600 - 4500
- Temp
- up to 650 °C / 1200 °F
- End
- BW, SW, RTJ, RF
- Standard
- ASME B16.34
Main Steam Valve
Gate / globe / check · pressure seal bonnet
- Body
- A182 F22, F91, F92
- Size
- NPS 2-24 (DN 50-600)
- Class
- Class 1500 - 4500
- Temp
- 540 - 650 °C for USC main steam
- End
- BW
- Standard
- ASME B16.34
Feedwater Valve
Gate / globe / check · pressure seal bonnet
- Body
- A105N, A182 F11, F22
- Size
- NPS 2-20 (DN 50-500)
- Class
- Class 1500, 2500
- Temp
- 150-300 °C typical
- End
- BW, RTJ, RF
- Standard
- ASME B16.34
Stop-Check Valve
stop check · pressure seal bonnet
- Body
- A182 F22, F91, F92
- Size
- NPS 2-16 (DN 50-400)
- Class
- Class 900 - 2500
- Temp
- up to 620 °C / 1148 °F
- End
- BW, RTJ, RF
- Standard
- ASME B16.34
The joint gets tighter as line pressure rises
Above roughly Class 900 a bolted bonnet needs impractical bolt load and loses preload to every thermal cycle. A pressure seal bonnet inverts the problem: line pressure does the sealing work.
Where these valves go
A valve is selected for a position in a system, not for a product category. Each page gives the governing condition and the constructions that belong there.
| System | Governing condition | Secondary |
|---|---|---|
| Thermal Power | 17-31 MPa (subcritical to USC) | 540-610 °C |
| Nuclear Power | 6 - 8 MPa, saturated | 280 - 300 °C |
| Cogeneration & CHP | 4-14 MPa typical | 440-540 °C typical |
| Boiler & Steam Systems | 4-20 MPa depending on unit type | Saturated and wet steam, flashing across the seat |
| High-Pressure Steam | Class 900, 1500, 2500, 4500 | 15-45 MPa depending on class and temperature |
| Boiler Feedwater | Above drum pressure plus static head plus losses | 150-300 °C |
| Steam Turbine | Main steam conditions at the stop valve | 3-8 typical on a utility machine |
| Petrochemical & Refining | 200-550 °C typical for hot service | Class 300-2500 |
| Coal Chemical | 200-550 °C in the utility systems | Steam, syngas, ash and slag-bearing streams, process water |
Every claim here should be checkable
No service-life figures, no zero-leakage claims, no production capacity numbers. What there is: parameters marked by how firm they are, standards listed only where they apply, and the document that proves each one.
01
Traceable material
Heat number from mill certificate through machining to the nameplate, verified by PMI on every pressure part rather than on a sample.
How to check the chain 02
Recorded heat treatment
Furnace charts, PWHT charts per weld, hardness survey afterwards. On F91 and F92 this is the only production check that the material will perform.
Why it decides everything 03
Tests reported properly
Actual pressure, actual duration, observed leakage against the allowable rate, gauge calibration reference. Not a pass mark.
What a credible report shows 04
Certificates, once verified
The certificates page currently lists nothing, because nothing has been verified for publication yet. That is deliberate.
Read whyWritten for the person doing the selection
Each article states its scope and its limits, names the standards it relies on, and carries a review date.
- F91 vs F92 Valve Materials
How F91 and F92 differ, where each is appropriate, why heat treatment decides whether either performs, and what records to demand on a creep-grade valve order.
- What Is a Pressure Seal Bonnet?
How a self-energizing pressure seal bonnet works, why it takes over from bolted bonnets above Class 900, how it is assembled and disassembled, and what its real limitations are.
- API 600 vs API 602 vs ASME B16.34
Three standards routinely listed together on valve datasheets. What each one actually governs, how they stack, and the misquotation to watch for on pressure seal valves.
- Forged vs Cast Valve Bodies for Power Plant Service
When forging genuinely outperforms casting in valve bodies, when it does not, what the terminology actually means, and how to write the requirement into a specification so it means something.
- Material Selection Guide
How body and trim materials are actually chosen for power plant valves, the constraints beyond temperature, and the questions that decide the answer.
- Class 1500 Valve Selection
What Class 1500 actually specifies, how the rating changes with material and temperature, when Class 900 or 2500 is the correct choice instead, and what changes in the valve itself.
Send a valve list, get a line-by-line answer
Including the lines where we would need a deviation, and the lines where we think the wrong valve has been specified. That second category is the useful part.