Question 1

What is a lift check valve and how does it work?

Accepted Answer

A lift check valve is a check valve in which the disc, sometimes called a lift, is lifted off its seat by the higher pressure of inlet or upstream fluid to allow flow to the outlet. A guide keeps the disc motion on a vertical line so the valve can reseat properly. When pressure drops or reverses, gravity and back-flow force the disc back onto the seat to stop reverse flow.

Question 2

What sizes and pressure ratings are available for SHIELD Lift Check Valve Series LT?

Accepted Answer

SHIELD Lift Check Valve Series LT is available in sizes 2" to 12" (DN50 to DN300) with pressure ratings up to ASME Class 900. Temperature range is -321°F to 1100°F (-196°C to 593°C).

Question 3

What end connections and design standards does the SHIELD Lift Check Valve comply with?

Accepted Answer

The valve offers flanged ends per ASME B16.5/B16.47, EN1092 and JIS B2212, or butt welded ends per ASME B16.25 and EN12627. Design and manufacturing standards include API 594, API 6D, ASME B16.34, EN12334, BS3356, BS1868 and JIS B2074. Testing follows MSS SP-61, API 598, EN 12266-1 and JIS B2003.

Question 4

What materials are used in the SHIELD Lift Check Valve?

Accepted Answer

Body material is carbon steel or alloy steel. Stem material is forged stainless steel. The wedge/trim and seat materials follow API 600/602. The renewable seal welded seat is standard with Stellite 6, and an optional screwed-in seat is available. Cover bolting is manufactured from alloy steel.

Question 5

What industries and applications is the SHIELD Lift Check Valve used for?

Accepted Answer

SHIELD Lift Check Valves are recommended for steam, air, gas, water and high-velocity vapour lines, and are widely used in petrochemical, oil and gas, water treatment, power generation, marine and HVAC systems. They are commonly used in piping systems where globe valves are used as flow control valves.

Question 6

Does the SHIELD Lift Check Valve offer bubble-tight shutoff?

Accepted Answer

Yes. The metal seated design of the SHIELD Lift Check Valve delivers unidirectional bubble-tight shutoff, and the design has been fire-tested per API 6FA and API 607.

Question 7

Can SHIELD supply lift check valves to international standards such as API, ANSI, DIN, JIS and EN?

Accepted Answer

Yes. SHIELD manufactures lift check valves to API, ANSI, DIN, JIS and EN standards, and can supply valves compliant with NACE MR-0175, NACE MR-0103 and ISO 15848 for sour service and fugitive emissions requirements.

Question 8

How do I request a quote for SHIELD Lift Check Valves?

Accepted Answer

You can request a quote through the contact form on this page, or email sales@shieldvalves.com. Please provide the valve type, size, pressure rating, body material, end connection, quantity, application and delivery destination so our engineers can recommend the optimal configuration.