Route the discharge piping in as short and direct a route as possible. Use the same pipe size as the outlet of the pump. In installations where the discharge piping is in excess of 50 feet, use the next larger size pipe to minimize friction losses downstream of the pump. Always use pipe or hose that is designed for your particular pressure requirements. Inadequate pressure ratings can allow hose or pipe to fail resulting in personal injuries or equipment damage. Normal hose pressure ratings are clearly marked on the outer surface of the hose. Working pressure ratings for steel pipe can be obtained from the manufacturer or from the chart below.
Always use a pressure gage in the pump discharge line. A properly functioning gage mounted at the pump (and before any valves) is required to accurately determine the operating pressure of a pump.
Insure that all piping is supported independently of the pump to reduce vibrations and strain on the pump itself. The use of elbows, nipples, unions, or other fittings should be kept to an absolute minimum. Avoid short radius 90° elbows; use two long radius 45° elbows instead. To help isolate mechanical and hydraulic vibrations, FMC Technologies recommends the use of flexible hose connections between the pump and any rigid piping.
A properly adjusted pressure relief valve or rupture disc must be installed directly downstream of the pump to prevent damage or injuries resulting from over pressure or dead-head conditions. The relief valve by-pass line must be as large as the pipe outlet of the relief valve. Never install valves in the bypass line or between the pump and relief valve. FMC Technologies recommends that the by-pass be returned to the suction tank or drain, not back into the pump suction line.
Multiple Pump Systems
Special care must be taken to avoid problems when operating multiple reciprocating pumps using common suction and discharge piping headers. It is recommended that the user contact FMC Technologies or other suitable industry consultants for assistance with the design of the system and installation of pump in these situations.
