17 Oct,2026

Quick Answer Check valve cracking pressure is the differential pressure across the valve at which the first detectable forward flow occurs under specified test conditions. With the outlet vented to atmosphere, upstream gauge pressure may approximate this differential. It is not the same as full-open pressure drop or reseat pressure, and it changes with valve […]

15 Oct,2026

Quick Answer Check valve chattering is the rapid, repeated opening and closing of the disc, usually caused by unstable flow forces rather than one defective part. The most common causes are an oversized valve running below its minimum stable flow, pulsating flow, poor installation or worn internals. Confirm the noise pattern first, then compare actual […]

13 Oct,2026

Quick Answer A cryogenic ball valve design is suitable for LNG only when the complete valve configuration is qualified for the minimum service temperature. Verify material suitability for the minimum design temperature. Review grades, heat treatment and traceability, together with impact-test results where required, or the documented exemption permitted by the applicable code and project […]

10 Oct,2026

Quick Answer Globe valve trim is the set of wetted parts that control flow and shutoff: the disc, seat faces, stem and backseat. For severe service, choose trim by damage mechanism, not by material name alone. Erosion, cavitation, galling and thermal cycling each call for a different answer. A plug disc usually gives more progressive […]

10 Oct,2026

Quick Answer Globe valve pressure drop is the head loss caused by fluid passing through the body, seat and throttling element at a stated flow. Cv shows how much flow a valve passes at a defined pressure drop, while the flow path, disc position and trim set the actual loss. A low Cv at the […]

08 Oct,2026

Quick Answer: A low-emission ball valve is only as strong as its evidence. Match the test standard to the valve design, confirm the report covers the exact size, class, materials and stem seal you are buying, and separate type-test qualification from production testing. A logo is not a report for the valve you will install. […]

07 Oct,2026

Quick Answer In the metal seated vs soft seated ball valve decision, the seat sets the practical limit. A soft seat uses a polymer ring against the ball for tight shutoff and low torque at lower cost, but heat, pressure, solids and chemical attack shorten its life. A metal seat uses hard-faced metal contact for […]

21 Sep,2026

Fire-tested valves are designed to limit external and through-seat leakage to the levels permitted by the applicable standard during and after a specified fire-test sequence. Widely used fire-test standards include API 607 for quarter-turn valves and valves equipped with nonmetallic seats, API 6FA for applicable API 6A and API 6D valves, and API 6FD for […]

20 Sep,2026

An API  600 gate valve is a bolted-bonnet cast-steel gate valve designed for petroleum and natural gas service where full-port openings, heavy wall sections, and large stem diameters are required. The applicable size and pressure-class range should be stated according to the edition of API 600 used for the project.  PANS Valve manufactures API 600 […]