VENTURI / Technical insight
How to Select an ANSI Metal-Seated Gate Valve
Quick answer
An ANSI metal-seated gate valve is considered for full-open/full-closed isolation. Selection depends on operating temperature, body and trim materials, connections and required leakage performance, not only size and pressure class.
What does “ANSI gate valve” specify?
“ANSI” alone is not a complete specification. State the applicable design, pressure-temperature, flange and face-to-face standards separately. API 600 addresses a defined steel gate-valve design; ASME B16.34 covers pressure-temperature and other valve requirements. Do not assume every gate-valve model falls under API 600.
How should Class 150, 300 or 600 be assessed?
A Class number is not the working pressure in bar. Check normal, design and start-up pressure-temperature pairs against the selected material rating. Body alloy, gaskets and trim can impose different limits even within the same class. A higher class does not correct an incompatible material.
Why select the metal seat and trim together?
Trim identifies the material arrangement of seating surfaces, stem and other design-specific internals. Corrosivity, particles, temperature and cycling affect selection. Metal seating does not mean absolute zero leakage under all conditions. Specify acceptable seat leakage with the test standard, medium and direction.
Check throttling duty and installation space
A standard isolation gate valve is not a substitute for a control valve when held partly open. Assess control duty separately. For a rising stem, check overhead travel, handwheel access, maintenance clearance and actuator space on the drawing. Flange diameter alone does not establish interchangeability.
What should a stock enquiry include?
Send the tag, DN/NPS, class, facing, medium, pressure-temperature conditions, body/trim preference, quantity and required date. For replacement, add the nameplate and face-to-face dimension. Venturi offers stock supply options for metal-seated gate valves; availability for the selected configuration and quantity is confirmed with the quotation.
| Check | Information for the decision |
|---|---|
| Pressure class | Class + material + operating temperature |
| Connection | Facing + dimensions + face-to-face |
| Acceptance | Trim + test method + leakage criterion |
Frequently asked questions
Does Class 150 mean 150 bar?+
No. Allowable pressure comes from the applicable material and temperature rating.
Is a metal-seated gate valve chosen for throttling?+
It is generally selected for isolation. Continuous throttling needs a separately assessed control design.
Are matching size and class enough for replacement?+
No. Connections, face-to-face length, materials and service conditions must also match.
Contact Venturi for selection and technical verification against your application requirements.
