Advice on domestic water pump please

[stig44]

I have a house in Nong Khai. We are two retired people only living here, semi-permanent. Guests are referred to a Guest house nearby. The water pressure from District is about 0,3 - 0,4 kg, surprisingly constant. I would like to have 1 kg, not more because I had problem with the plumbing before.

It seems as the only two pumps I have looked at, Mitsubishi WP-105Q3 and EP-155Q3, will give pressure up to 1,9 Kg. Can this be adjusted down? How big storage tank is built-in?

Do I need a storage tank as well?

Anything else of great importance?

[Crossy]

Pressure switch is usually adjustable so no problem there.

No storage tank is included with these pumps, they do have a small pressure tank to even out the 'humps' when the pump cycles.

Pumping directly from the mains is not recommended (and likely illegal anyway) as there is a danger of sucking dirty water into the system if the supply is off. Instead you should install a storage tank fed from the mains and pump from that.

Something like this:

The bypass non-return valve (optional) allows you to use city pressure if the power is off or the pump requires service.

If the supply is generally reliable you don't need a very big tank, say 500 L. We have 5200 L due to long outages and the fact that during the day our village pressure won't actually make it to the top of the tanks.

[Pib]

If you are going to mess with the pressure switch setting, which if like the switch on my WP255, then it's the screw on the very top of the spring. There is also another smaller screw down the switch assembly a little bit used to adjust the span between the lower and upper pressure points. I really wouldn't mess with the pressure switch setting "unless you buy a pressure gauge" to check your adjustments. And then if the pump just doesn't seem to act right after the adjustment, you then can set the switch back to its original pressure settings.

[stig44]

Thanks a lot!

One problem solved, the pressure. One new problem occurred, a storage tank. Like always when running a project in Thailand.

Any idéa what the whole system is going to cost me? 10 000 baht or more?

[wayned]

You should be able to do it all for just under 10000 baht if you DIY. The pump is around 6000 plus the tank and plumbing.

[Crossy]

Our smaller tank (1000L) was B3990 at Homepro, you can get cheaper ones.

10k is a reasonable budget.

Do get decent bronze valves at least for the tank outlets, the PVC ones do fail and you don't want 1000L of water all over the place.

And don't forget to fit maintenance unions to your pump so you can remove it for maintenance http://www.thaivisa.com/forum/topic/567711-pump-service-unions/?p=5459547

[MichaelJohn]

If you're installing a pump you must have a tank - if not you will suck the water out of your neighbours washing machine when the mains is low!!!!

Like the above says - HomePro have many choices dependant on size and intended location. I have 2 x 1,100 lit so there can be settlement in one tank whilst we use the other (due to sediment in our village water).

I would strongly suggest you get a variable speed pump (sorry, about double the cost!) otherwise your pump "pulses" - you can search Google for "Water pump short cycling" a variable speed pump adjusts it's cycle to meet the demand i.e. cycles slowly when the tap is on slowly so it last longer.

A final suggestion; if you're half descent at DIY then install it yourself; there's nothing diffilcult and you understand you installation :-)

Good luck.