Standards For End Suction Pumps

An end suction pump full of isolation valves, vibration isolators, a suction strainer, long-radius ell and reducer at inlet, spring-supported inertia block, drain pan, and also other amenities normally connected with hydronic service is just one stage pump with only 1 impeller. Isolation valves, as appropriate, can be butterfly, gate, plug, or ball valves, dependant on line size and duty requirements. The weight with the piping for the vibration isolation fittings is usually supported by overhead suspension.


A strainer is needed to collect debris within the system. The strainer has a provision for blowdown, that may allow loose debris for being flushed in the strainer if your pump inlet valve is closed and backflow from your discharge from the pump over the flush valve occurs. The flush valve is commonly a 2-in. diameter or larger ball valve installed that includes a piping “tail piece” routed into a floor drain for spill containment. The screen inside strainer must be specifically selected to be used in a water system. If a strainer is used in a very condenser water system, it will have openings inside larger than that related to chilled water service. Often the strainer in the cooling tower basis suffices for this reason, along with the one within the piping is not required. Since strainers are offered integral to air separators and pump suction diffusers, drawings and specifications really should be carefully coordinated to ensure that merely one strainer is installed inside a chilled or trouble hydronic system.

Pump Inlet

An end suction pump requires the straight amount of pipe to the pump suction or possibly a suction diffuser. If a straight pipe section feeds the pump, the straight pipe section really should be at least three pipe diameters long, eat and drink via a long radius elbow, and include a reducer fitting in the pump inlet. All of these promote uniform flow to the pump impeller. Depending upon the weight related to the pump inlet piping through the vibration isolator downward, a stanchion pipe support are usually necesary. If it is required with no spring-isolated inertia pad is utilized, the stanchion needs to be supported in the pump base. Normally, with small pumps, a spring-isolation inertia pad is not required.

Pump Discharge

It frequently occurs practice and necessary in hydronic systems to utilize an increaser on the pump outlet. This is because of an noise consideration regarding high-velocity flow at pump discharge. A check valve is required in the pump discharge when pumps will be in parallel or when water have to be retained inside a system and keep it full, for example for a cooling tower mounted at rooftop level above a mechanical equipment room.

Pressure Ports

Provisions must be made with all pumps for measuring differential pressures making sure that pump flow can be determined on the manufacturer’s pump curves. The arrangement allows just one gauge to get used for pressure measurements. The use of Pete’s plugs is usually recommended in situations where pressures will not be excessive (<200 psig) and operating temperatures will permit it. Other ports and taps are now and again available inside the pump suction and discharge flanges from the pump. When they exist, they needs to be utilized for pressure measurement over the pumps, because manufacturer has probably utilized measurements produced in these locations for generation of pump curves.

Piping Isolation

Piping vibration isolation fittings, normally consisting of any rubber bellows and often mounted within a stainless-steel braided wire jacket where service limits want it, are offered from a variety of vendors. One inexpensive approach to allow for piping vibration isolation and noise containment in which the amplitude from the vibration is small is via using grooved couplings, one installed on the pump and another one in the top in the discharge pump riser where it’s going into a manifold or constitutes a change in direction. Use of grooved couplings, however, can also be constrained by fluid service limitations along with the amplitude with the vibration anticipated.