Diesel Tank Drain Query

[system 4-50]

My diesel tank has a drain line fitted by the builder. I need to drain a bit to get any water that has accumulated out. I have come to use it for the first time since the boat was built (in 2010) and I am a little puzzled.

It has a valve and then a plug, as per BSS requirements. The valve is a simple quarter turn gadget with a red plastic handle that looks a bit like a bubble tester knob, and looks to be designed for the job. It has a female end that has a small metal plug screwed into it. The plug is black and has square not hexagonal flats that take a 10mm spanner approx. Unfortunately I don't have a photo of it.

My question is, what is the best way of getting a plastic tube onto it? Is the fitting a standard component of known size?

The location is such that I can't get a collecting vessel under it directly.

[ditchcrawler]

The plug will be a standard male BSP thread anything from a quarter to three quarters of an inch depending on valve size. The valves sometimes have their size stamped on the body, not all do.

[Neil Smith]

Take the bung out and replace with a hose tail that will enable you to push a plastic or rubber pipe over it, you then put this in a can for draining.

 

Neil.

[bizzard]

Ideally done when in dry dock when any water should come more forward with the more level attitude of the boat. Assuming the tap faces forward.

[Chewbacka]

If the plug is about 11mm diameter it is probably 1/4"bsp.

[IDS]

Don't get your hopes up too much. I found that when I drained my tank using the provided pipe and bsp plug (no tap fitted!) it became obvious that it didn't drain the bottom of the tank. I used a drill pump with some 15 mm copper pipe through the filler to get to the bottom of the tank (got an extra 15 litres out.This was actually a very easy way to do it.

[system 4-50]

Thanks for that. I'll start with a 1/4" BSP to spigot and see how it goes. Yes, the tap faces forward. Must remember to fill the water tanks to bring the bow down.

[Guest]

Don't get your hopes up too much. I found that when I drained my tank using the provided pipe and bsp plug (no tap fitted!) it became obvious that it didn't drain the bottom of the tank. I used a drill pump with some 15 mm copper pipe through the filler to get to the bottom of the tank (got an extra 15 litres out.This was actually a very easy way to do it.

Similar experience to yourself. I always use a pump and piece of metal pipe thru filler. I never use the drain plug these days.

[Slim]

Or use a Pela oil suction pump. You can direct the probe to any part of the tank (within reason) and you get to the very bottom of the tank not the level that the drain pipe/ tap is.

 

 

Frank

[bizzard]

Or use a Pela oil suction pump. You can direct the probe to any part of the tank (within reason) and you get to the very bottom of the tank not the level that the drain pipe/ tap is.

 

 

Frank

Indeed, this is the best way to finish off. The lowest part of the drain tap in its bush will be at least about 3/4'' above the tanks bottom plate.

[Guest]

Or use a Pela oil suction pump. You can direct the probe to any part of the tank (within reason) and you get to the very bottom of the tank not the level that the drain pipe/ tap is.

 

 

Frank

#the very same. One of the best bits of kit on our boat.

[Dave Bebb]

When i did my tank i bought a wet and dry vac from b and q cost about £ 20 , took off the brass fitting what the filler cap screws to and just left a bigger hole .I then put a plastic extension pipe on the vac so it could reach the bottom of the diesel tank had two 5 gallon drums to put all the water and bugs to go in .There must have been 3 ins of water and like a red jelly in the bottom of the tank . PS my engine keeped cutting out to much crud in the bottom of my tank that was three years ago she still running fine