Mounting - Milton Roy PRIMEROYAL Instruction Manual

Suction piping must be absolutely airtight to ensure accurate pumping. After installation,
test suction piping for leaks with air and soap solution.
Discharge Piping
Install pipe large enough to prevent excessive pressure losses on the discharge stroke
of the pump. Maximum pressure at the discharge fitting on the liquid end must be kept at
or below the maximum pressure rating shown on the pump data plate.
The pump will not deliver a controlled flow unless the discharge line pressure is greater than the
suction line pressure. Piping should be arranged to provide at least 5 psi (35 kPa) positive
pressure differential between the discharge side and the suction side. There are a number of ways
to create an artificial discharge pressure, such as by installing a vented riser or a back pressure
valve. (Please consult Milton Roy Flow Control Division for recommendations to increase back
pressure in slurry applications.)
When pumping water-treating chemicals directly into boiler drums, use one liquid end
assembly for each boiler drum. Discharging into a manifold having the slightest pressure
difference between its several discharge connections can diminish metering accuracy as the
outlet with the lowest pressure will receive more liquid than the other outlets.
Vented Risers
A vented riser is simply a vertical extension of the discharge pipe into an open tee. The other
side of the tee goes to the process. Practically maintenance-free, this device prevents siphoning
and provides an artificial discharge head; however, a clogged or closed line may cause the riser to
overflow. Therefore, substitute a pulsation dampener and back pressure valve for a vented riser
when pumping hazardous liquids
Check Valves
A check valve should be installed at the point where the discharge line enters a boiler or
other high-pressure vessel. This will prevent back flow through the discharge piping and will
isolate the pump discharge from system pressures (a safety consideration).
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