Be careful to limit the suction to 4' in a suction-lift application, and a foot valve must be used in a top-mount application. Limit the length of a flooded suction to 6 or 7' and use an adequately sized line with minimized bends, elbows or other restrictions.
When considering the piping, the safest rule-of-thumb for selecting suction pipe size is to use one size larger than the pump suction connection. For discharge piping, specify piping that is suitable for the discharge pressure.
Other accessories to be considered when planning a metering-pump installation include:
- Suction strainer.
- Flanges, unions or compression fittings
- Isolation valves.
- Calibration column.
- Relief valve.
- Back-pressure valve.
- Pressure gauge.
- Pulsation dampener.
- Injection quill and check valve.
- Will the new program operate at the same feed
rates as the previous one?
- Is the equipment properly sized for the new
- How well has the equipment been operating?
- Are there any problems with reliability, accuracy or unusually high maintenance requirements?