Cla-Val Series 582 Two-Door Wafer Check Valve

A compact two-door check valve for large pump lines

The Cla-Val Series 582 two-door wafer check valve has torsion springs that force the two doors shut before flow reverses, which reduces the water hammer potential of single-door swing checks. The two-door design also shortens the travel from open to shut-off for a quicker response. Extremely short in lay length, it is a compact and economical solution that fits between ANSI flanges.

Cla-Val lists low head loss, a resilient seat, non-slam closure and stabilizer spheres that prevent vibration wear. The valve meets the federal mandate limiting lead in drinking water.

Technical specifications

Construction and pressure classes

Sizes 2 to 6 inch are dual rated to 150 and 300 pressure classes and have alignment grooves for mounting between 150 or 300 lb flanges. Sizes 8 to 36 inch are rated to 150 class. The body is ductile iron ASTM 536 65-45-12, the doors are aluminum bronze ASTM B148, the disc and seat are stainless steel with a resilient Buna-N seat molded to the body, and the springs are stainless steel. The standard coating is a two-part epoxy inside and outside. A lug pattern is available on consultation.

Although lighter than globe-style swing check valves, the valve is designed for heavy-duty applications. From 10 inch and larger the valve has a tapped hole for fitting a lifting eye bolt, which eases installation.

Selecting a two-door check

The datasheet includes a head loss chart for water flow in gallons per minute for sizes 2 to 60 inch, so the pressure drop at the design flow can be read before the size is chosen. The dimension table lists, for each size and class, the principal dimensions and weights in inch and metric units. The specification wording states that valve doors open with flow and that, on pump shutdown, the torsion spring shuts the doors before reverse flow starts.

If metal-to-metal seating or installation with flow upward is needed, compare the Cla-Val Series 580 spring-loaded silent check, which is rated for either orientation. For pump stations where a controlled opening and closing rate is needed, the hydraulic 81-02 is the alternative.

Related Cla-Val products: Cla-Val Series 580 Silent Wafer Check Valve and Cla-Val 81-02 No-Slam Hydraulic Check Valve.

How the two-door design reduces water hammer

In the Cla-Val Series 582, two spring-loaded doors swing open on a central hinge when the pump starts. Heavy-duty stainless steel torsion springs hold the doors closed. On pump shutdown, Cla-Val’s specification states that the springs shut the doors before reverse flow starts, giving non-slam closure. Because each door is only half the bore, the travel from fully open to shut-off is shorter than that of a single-door swing check, which gives a quicker response and reduces the water hammer potential that normally occurs with single-door swing check valves. Stabilizer spheres prevent vibration wear while the doors are open.

Materials and construction

• Body: ductile iron to ASTM A536 65-45-12
• Doors: aluminium bronze to ASTM B148
• Disc and seat: stainless steel
• Springs: stainless steel; two or more springs are used on sizes 14 in (350 mm) and larger
• Seating: resilient Buna-N, watertight and molded to the body
• Coating: two-part epoxy interior and exterior as the standard offering

Cla-Val states that the valve meets the US federal mandate limiting lead in drinking water, which is relevant for potable water pumping stations.

Installation notes from the specification

The Series 582 is a wafer design that fits between ANSI flanges and has an extremely short lay length, so it saves space compared with a full-body swing check. Sizes 2 in to 6 in have alignment grooves for mounting between Class 150 or Class 300 flanges. Sizes 8 in to 36 in are mounted between Class 150 flanges. Valves 10 in and larger are supplied with a tapped hole for a lifting eye bolt. A lug pattern is available on request from the factory. When asking for a quotation, please state the line size, flange class, maximum working pressure, the medium (raw water, treated water or wastewater) and the pump flow rate, so the head loss can be checked against Cla-Val’s flow chart.

Where the Series 582 is typically used

A two-door wafer check valve is normally placed on the discharge side of a pump, between the pump and the isolating valve, to stop the line from draining back through the pump when it stops. Typical locations include municipal water supply and booster pumping stations, irrigation networks, cooling water circuits and treated water transfer lines. Cla-Val summarises the main benefits as low head loss, a resilient seat, non-slam closure and stabilizer spheres that prevent vibration wear. Although it is lighter than a globe-style swing check, Cla-Val states that the valve is designed for heavy-duty applications. For larger pipelines, the compact body and short face-to-face dimension also reduce the weight that the pipe supports must carry and make removal for inspection easier.

Documents and quotation

The Series 582 data sheet is attached. Give the size, pressure class, flange standard, flow and fluid when requesting a quotation, and note if a lug body is required. As general practice, also check the clearance to adjacent fittings such as an elbow or pump nozzle, because the doors swing inside the flange bore, and confirm that the mating flange class (125/150 or 250/300 for the 2 to 6 inch sizes) matches the pipe. Related valves are listed under Fittings & Valves.