Bilge Pump: Ib lub twj tso kua mis tsim nyog rau lub nkoj

Bilge twjyog qhov tseem ceeb tshaj plaws rau lub nkoj vim lawv ua kom lub nkoj ntab. Muaj ob hom kev yooj yim:centrifugalthiabdiaphragm. 

Cov twj centrifugalsiv impellers, thiab feem ntau yog hluav taws xob lossis mechanically powered. Lawv nyob ntawm qhov chaw hluav taws xob lossis lub zog hluav taws xob ncaj qha xws li los ntawm lub cav lossis lub tshuab hluav taws xob. Thaum txhim kho cov twj siv hluav taws xob, kev sib txuas ntawm kev sib txuas yog qhov tseem ceeb. Kev sib txuas yuav tsum tsis txhob muaj dej tsis sib haum, thiab ruaj khov kom ruaj khov kom ntau li ntau tau los tiv thaiv kev cuam tshuam nrog lub twj tso kua mis thiab / lossis ntab hloov.

Some electric marine pumps include an internal float switch which, of course, activates the pump when water rises. These are usually smaller pumps, and the internal switch design can render them more susceptible to blockage and sticking due to bilge debris. Most bilge pumps require a separate float switch allowing easy testing of the switch and pump (manually lifting the switch arm) and separate installation positions for the switch and pump. For example; wisdom holds that two pumps may be better than one. Both pumps can be strategically located in the bilge, but the switch for one pump can be higher than the other. This allows automatic operation of only one pump for regular duty, thereby reducing current draw and the life of only the one pump. As any long time boater knows, emergencies happen. When water intake exceeds the capabilities of the primary pump, the higher switch will activate the back-up pump.  

There are many type of centrifugal pump can meet the requirement.  vertical pump( CLH, CLZ, CQX ) horitontal pump (CWZ, CWL, CIS) etc.

 For smaller boats or those without power such as sailboats, rowing boats, etc., a manual suction or hom diaphragmua haujlwm zoo. Cov twj no tuaj yeem pheej yig thiab nqa tau yooj yim. Lawv kuj muaj qhov zoo ntawm qhov tsis yooj yim los ntawm cov khib nyiab hauv lub bilge. Lawv txhim khu kev qha thiab ua haujlwm zoo yog tias koj tuaj yeem siv zog rau lawv. Qhov teeb meem yog, ntawm cov nkoj loj, koj tuaj yeem siv lub twj tso kua mis ntev npaum li cas? Thaum cov twj tso kua mis no tseem tuaj yeem siv tshuab lossis hluav taws xob, lawv feem ntau loj dua thiab hnyav dua, yog li cov twj centrifugal yog qhov kev xaiv ntau; tab sis kev xaiv zoo. Yog tias tsim nyog, xav txog ob hom.

This brings us to another point. When purchasing pumps, do not skimp; as important as life jackets, rafts, ELT's and VHF's can be in an emergency, the good bilge pump is often your first line of defense against losing a boat and sometimes more. At the very least, in a flooding situation, good pumps can buy you time for options.

It is important to understand that advertised marine pump ratings in gallons per hour (GPH) are not accurate for normal use. Pumps are tested and rated in laboratory conditions with short outflow pipes on the horizontal. Under actual conditions we have to consider "head" which means overcoming both the friction of the outflow tubing and gravity to raise the water to the through-hull fitting. Common bilge pump tubing is a corrugated design which creates a great deal of friction. Smooth bore tubing is more expensive, but better.

Also, consider friction loss as outflow is restricted at the smaller diameter through-hull fitting. Now we have to lift the water from the bilge to overboard, usually through a through-hull fitting. Holes in a boat near the water line are to be avoided as much as possible. The through-hulls for your pumps should be at least eight inches above the waterline. For mono hull sailors, don't forget you're going to heel. For small boaters or commercial applications, remember that the water line will be higher if you heavily load the boat. You should always use a "safety loop" when piping overboard. That is, the piping should be looped higher than the through-hull to prevent water coming in if the through-hull is submerged. This loop, of course, increases the head, so it must be considered when choosing a pump.