Cast Steel Lift Check Valve: An Overview

A cast steel lift check valve is a self-acting non-return valve whose closure is a disc that travels straight up in a guide cage; forward flow raises the disc off its seat and reverse flow lets it fall back, and the guide keeps it centred on the seat every cycle. Because it needs no stem, no packing and no actuator, it is a cheaper valve to keep in a line than a globe valve of the same duty, and the part buyers most often forget on the datasheet is not the operator but the orientation. The build on this page is cast ASTM A216 WCB to API 594 in NPS 2 to NPS 24 and Class 150 to Class 2500, with ASME B16.34 carrying the pressure-temperature rating and ASME B16.10 the face-to-face length.

Design Standard

Cast Steel Lift Check Valve Drawing

Material of Construction 

*HF: Hard-faced with stellite 6 or equivalent.

Note: Materials listed in the table are general. When ordering, please contact SNY sales or technical team to confirm the details.

Dimension & Weight

CLASS 150

CLASS 300

CLASS 600

CLASS 900

CLASS 1500

CLASS 2500

Flange Dimensions ASME B16.5&B16.47

Dimensions are in inches

Class 150

Class 300

Class 600

Class 900

Class 1500

Class 2500

Note: Due to quick development of products, the data in our catalogue may be updated. GNEE reserves the right to change the design, material, or specification without notice and free of obligation to furnish or install such changes on products previously sold.

Test and inspection

Send your size, class and line orientation

FAQ

What standard covers a cast steel lift check valve?

A cast steel lift check valve is covered by API 594, which describes the flanged and wafer check valves including the guided-lift disc, in NPS 2 to 24 and Class 150 to 2500. API 602 and BS 5352 cover small-bore forged lift checks, the body is ASTM A216 WCB, and the pressure-temperature rating comes from ASME B16.34.

Can a lift check valve be installed horizontally?

A bare lift check valve cannot be installed horizontally or on a downward run, because the disc returns to its seat only by gravity acting down the bore, so it must sit in a vertical line with upward flow. A spring above the disc returns the disc against any orientation, and that spring must be named on the order if the line is not vertical-up.

What is the cracking pressure of a lift check valve?

Cracking pressure is the minimum forward pressure that lifts the disc off its seat, and it is the line most often left blank on a requisition. A bare lift disc cracks at about 0.1 to 0.3 bar by its own weight on the vertical travel, which is higher than a swing disc; a spring-assisted disc cracks at 0.3 to 1.0 bar and reseats against mild reverse flow. Without a stated value, an oversized valve can chatter in its cage and leak.

How is a lift check valve different from a swing check valve?

A lift check valve moves its disc straight up in a guide cage and is built for vertical upward flow, with a higher pressure drop and a tighter seat at high pressure. A swing check valve pivots a disc on a hinge, fits a horizontal main, gives a lower pressure drop and is the lower-cost choice on low-velocity water mains. The pressure class is the same; the closure element and the orientation differ.

Why does a lift check valve have a higher pressure drop?

A lift check valve turns the flow twice - up through the seat and around the guided disc - where a swing check passes the stream in a single arc, so the loss is higher at the same bore and velocity. The higher drop is accepted on vertical high-pressure duty where the tighter shutoff and the compact guided disc are worth more than the loss.

What leakage class does a metal-seated lift check valve hold?

A metal-seated lift check valve is accepted at ISO 5208 Rate D, 0.1 × DN mm³/s, which is 30 mm³/s at DN 300, tested by the API 598 method as a differential across the closed disc. A renewable PTFE or NBR insert reaches ISO 5208 Rate A, effectively bubble-tight. A requisition written to "API 598 Class VI" or "FCI 70-2 Class VI" should be rewritten to the ISO 5208 rate before the order is placed.

When should a lift check valve be chosen over a swing check?

Choose a lift check valve for a vertical-up high-pressure run, boiler feed or pump discharge where the guided disc gives a tighter seat and less slam, and where the higher pressure drop is acceptable. Avoid it on a low-pressure large-bore horizontal water main, where a swing check gives a lower loss at lower cost, and on a horizontal line without a spring, where it will not reseat.

Is a lift check valve good for water hammer control?

A bare lift check valve slams less than a bare swing check, because the guided disc travels a short fixed distance and is already aligned with the seat, so there is no swinging arm to accelerate. A spring above the disc returns it earlier still, and a dashpot removes the final strike; for a low-slam retrofit on a re-piped line, a dual-plate or axial check is the alternative.