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Pump Accessories

Suction Diffusers and Triple Duty Valves

Photo of Keckley PSD and TDV style pump accessories - a suction diffuser and a triple duty valve, respectively.


Use the buttons below to view the models available in your desired body material.

Suction Diffusers

Suction Diffusers

Triple Duty Valves

Triple Duty Valves

Cast Iron Suction Diffusers (ASTM A 126, Class B)

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Size Range Pressure Class End Connection Style
2"x1-1/2" - 20"x20" 125 lb. Flange PSD
1" - 36" 150 lb. & 300 lb. Flange FPSD

Cast Iron Triple Duty Valves (ASTM A 126, Class B)

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Size Range Pressure Class End Connection Style
2" - 20" 125 lb. Flange TDV


Keckley manufactures suction diffusers and triple duty valves (TDV) as pipeline and pump accessories. These provide specialized and unique functions different from other Keckley products.

Suction Diffusers

Keckley Style PSD suction diffusers mount to the suction side of a pump in either a horizontal or vertical position. They are designed to remove any foreign matter that may be hazardous to the pump or other system components, while providing the proper flow conditions to the pump. Where space is limited, the Keckley Style PSD can be used as an elbow (in some cases a reducing elbow) with a built in strainer for easy maintenance and system performance.

The Keckley Style PSD has integral straightening vanes to ensure uniform flow to the suction inlet of the pump. The Style PSD provides minimal pressure drop with its oversized body and screen, and is normally supplied with a 20 mesh 304 stainless steel removable start-up sleeve to help promote a cleaner, more trouble-free system. The Style PSD is furnished with a bolted cover and O-ring seal, cast supporting pads for easy mounting of standard ID support feet, and a plugged drain connection.

Triple Duty Valves

Keckley Style TDV triple duty valves are primarily required on the discharge side of a centrifugal pump in a hydronic heating or cooling system. The Style TDV functions as a shut-off valve, spring loaded silent check valve, and balancing valve.

The Keckley Style TDV has an automatic and silent operation. The disc will open when the line pressure is approximately 0.25 PSI. As the line pressure approaches zero, the spring will close the disc to prevent flow reversal and water hammer. The flow through the valve can be adjusted from bubble tight shut-off to full flow by the acme rising stem.

The center guided soft seal disc ensures that there is no leakage. The rising stem design includes an adjustable position indicator for accurate disc positioning for throttling service. The unit comes with a standard gauge taps at both the inlet and outlet sides and an NPT drain plug.

Keckley Style TDVs are constructed from rugged cast iron castings that are machined to exacting specifications. These bodies have drilled flanges that are in accordance with ASME B16.1. Keckley Style TDVs can be supplied in other body materials (Carbon Steel and Stainless Steel) upon request.


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