The key element in drafting is eliminating the air in the
pump system. Making sure all drains are closed and every inlet is capped
tightly is essential. Also, a well maintained primer will make the task of
drafting much easier. The primer is designed to remove air out of a pump so it
will be more effective on a dry pump. If the pump and suctions are partially
full of water, the primer will have to work harder in order to expel the water
and air mixture out of the plumbing.
There are a few accessories that will make the task of
drafting much easier. Lightweight suction hoses will allow the operator to see
the water coming into the pump. The operator should always make sure that the
suction hoses have a proper fitting gasket and that the suction hose is
threaded on tightly. The slightest amount of air coming in by the suction hose
threads will make it difficult to maintain prime.
Choosing the right strainer for the job is also another
key component to drafting. A barrel strainer can be used when there is a lot of
water and no chance of the strainer hitting the bottom. A floating strainer
should be used in a pond or lake in order to keep the suction off the bottom
where it could come in contact with sand. A low level strainer should be used
in the portable tank in order to get out as much water as possible.
The shorter the height between the surface of the water
and the center of the suction inlet, the easier the drafting operation will be.
The maximum lift should be below 20’ high. The horizontal distance is not an
issue so a porta tank can be placed in front or behind a fire apparatus. A
suction elbow can make that operation easier by saving the suction hose from
making a large loop by the operator.
How often does your department practice drafting
operations?
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