12 volt in line pump

I had a similar one on my last camper trailer pushing water through the hand pump. It then uses the one way valve in the bottom of the hand pump to keep prime, also if it loses prime, like on a rough track, it is simple to reprime it just by pumping the hand pump.
Make sure that you use a sprung 'momentary' type switch.

HI
I put a Whale in line pump in a c/van the same as last post under sink worked fine no bad noise just enough to let you no it was working
I also put one in my next c/van but the van pump was on floor and had to put Whale pump at water tank or put a stop reverse flow valve in which i did not do it also works fine being outside you have to listen to hear it i have a mixer tap in van which water comes up hot water side ( no hot water)
PS the Whale pump looks the same as the one above, I put a on/off switch near sink
cheers reggy2

That pump appears to be a close copy of the whale one, they are very reliable and go for years and years without problems.
The whale ones are actually rated for diesel and I use one on my aux tank to pump fuel into the main tank, it has been chugging away for about 6 1/2 years now. I've also got one on the water tank which has been in service for about 15 years as it has been in 2 vehicles now.
Beware of cheap copies as the innards may not be of good quality and may corrode with water sitting in them, the whale ones have stainless impellers.
Whitworths marine was the cheapest source when I bought mine.

I used a Rule version can't remember the flow rates but it can do water and diesel which has been really handy. They make a little buzzing sound that isn't too noisy

I use a similar one on my camper trailer, although mine isn't inline as such.

It doesn't pump to a very high head but it suits me as my tap is only just above tank height. It pumps about 4L/min and is reasonably quiet.

Thanks everybody for the replies and pic, much appreciated

Cheers