Hard Suction Hose - Strainers

Strainers

When being used in a drafting operation from a pool, portable water tank, or other uncovered water source, the length of hard suction hose farthest from the pump is usually attached to a strainer, to keep foreign objects in the water from being pulled into and damaging the pump. If used in a pond, stream, or other body of water, an appropriate flotation device must be used to keep the strainer below the surface and above the bottom, so that neither mud nor air are sucked into the fire engine's pump. When drafting from a solid-bottomed tank or pool, a strainer can safely rest on the bottom without suctioning mud into the fire engine's pump.

The United Kingdom official guidance is to:

• use ropes to take to the weight of the hose and the strainer, in order to avoid putting sideways loadings on the couplings;
• ensure that the strainer is a minimum of three strainer-diameters below the water surface to prevent air cavitation;
• to support the hose with packing, where necessary, when it crosses a wall or other obstruction to prevent an air pocket being formed.