Changes

PVC pumps

83 bytes added, 15:31, 10 August 2009
no edit summary
__NOTOC__
The name PVC pumps covers a large number of different hand pump designs, which have in common that most parts are constructed out of PVC. PVC is used because it is often cheap, and easy to work with. As PVC is less durable as other materials such as steel, a singe PVC pump should be used by a limited number of people. Because of the low price, PVC pumps are often used as family pumps. Sometimes other types of Plastic are used, such as ABS, which is UV resistant.
There are many types of PVC pumps, differing in design aspects such as direct action versus lever operated, piston rod versus piston pipe, single or double action, with or without a water seal. The valve designs vary from ball valves, rubber flap/butterfly valves and bicycle inner tube valves to bolt valves, pvc adapter valves, and washer valves.
==Technical specification==
An important issue with all PVC pumps is the tendency of PVC to become brittle when exposed to direct sunlight for some time. Some pumps, such as the Baptist and EMAS pump, solve this by having a concrete pillar around the PVC tube, and by constructing the handle part out of galvanised steel pipe. Other pumps, such as the Canzee pump, use special the UV-resistant PVCplastic ABS. The negative effects of sunlight can be partly avoided by shielding the pump from direct sunlight, by painting PVC parts, or by protecting the PVC in some other way. In Bolivia, a strip of cloth is wound around the PVC parts, and held together with a piece of metal wire.
Akvopedia-spade, administrator
3,247
edits