Burning the Bras Ears

We are all aware that capable electricians are as rare as hymens in a brothel but less obvious is the fact that hymens are relatively common items when compared with the availability of capable plumbers.

We tend to be a bit scared of electrons don’t we (well we should be)? I suppose it all goes back to the fact that, like ebola, we can’t see the little blighters but we know that they can do us a severe nasty if they get loose. As a result when we can’t find a good electrician we really do miss them.

Plumbers on the other hand deal with water and the danger is merely that we might get a tad damp or a squirt in the eye from some contumacious hosepipe. It is all just a bit of a bother that we have to learn to put up with. If we can’t find a real plumber we just say “firtling emma” and ask that ever so capable, highly experienced recycler of used cardboard boxes to install that submersible pump for us.

No wonder everywhere we look people are having aqueous adventures.

It is gratifying to note that members of the Bakso Rollers Association (knows as BRA for short) who, realising there is a distinct dirth of suitably skilled individuals around and not wishing to miss an opportunity, are doing a little bit of plumbing on the side to make ends meet.

At this point we should state that it is not true that the phrase “burning of bra’s ears” is some punitive action taken by the frustrated wives of bakso rollers demanding more respect from their husbands when they leave the toilet seat up but is, in fact, derived from the Association’s secret initiation ceremony for new members which involves the singeing of the inductee’s earlobes whilest hopping on one leg and singing “Uncle Joe’s meatballs keep us all aglow, give em to your granny and watch the bugger go…. etc,etc.”

In fact the BRAs have been doing us all a favour of late in leading a national campaign to train recalcitrant water to be more cooperative and to cease that incessant habit of flowing downhill or running away at the slightest opportunity. The project has been a little challenging to say the least however they have been nearly as successful as King Canute was with his maritime (or should that be antimaritime) endeavours.

That smartypants Isaac Newton he’s the one to blame – he was the one that invented gravity – and was promptly hit on the head with an apple for his trouble. Serves him right I say.

Difficult stuff water, it’s like a grumpy old bull, it is lazy and stubborn and difficult. It doesn’t want to be contained in a pipe, it runs where you don’t want it to go and managing it is like herding head lice.

I received an email from Paul highlighting a common problem:

“We have very low water pressure in our villa. We have a bore with a Shimizu PC-260 BIT automatic pump on it (I don’t know how deep the bore is or what the pump at the bottom is). We have one gas instant hot water heater supplying 3 bedrooms plus kitchen. The problem is that when one tap is running, i.e. the garden being watered or a shower running, then a second tap is turned on and virtually no water comes out. Also, the water pressure is so low that sometimes the gas water heater won’t even fire. A constant pressure water pump has been suggested but I am not sure about head pressure, litres per minute etc and need advice on a suitable replacement pump.”

I suspect that Paul’s problem is a flow problem rather than a pressure problem and is caused not by the pump but by unsatisfactory design of the piping.

We’ll come to the pipework in a minute but let us first consider the pump.

If the Shimizu pump is mounted in the pipe as it comes out of the bore then the Shimizu is the bore pump (there will not be another in the bore).

In such a system there will not normally be a water storage tank and the water will be pumped directly from the bore to the taps around the house. If it works this is fine, a low cost, simple system. It has a couple of drawbacks however. The water supply is totally dependent on the pump working and, if the power goes off, there will be no water. Also water can only be used at the maximum rate that the pump can deliver.

A Shimizu PC-260 BIT is a “jet” pump, it is a type used for bores where the water level is more than 9 metres but less than 30 metres below the surface. It has a flow rate of 75 litres per minute which should be plenty for most houses. Being a jet pump it can suck water from a depth of 30 metres and push water a further 30 metres above the pump giving a total “head” of 60 metres. The outlet pipe is 1.25 inches in diameter.

A pump of this type will come with a pressure tank on it (a steel canister about 20cms diameter and 25cms long) which has air in it and stores pressure, this has the effect of smoothing out the pressure if the supply from the water pump does not match the demand from the taps. It is a cheaper option than a constant pressure pump.

From the clear information we have been given it is highly likely that the problem is caused by the design (or lack of design) of the water system. It is probable that a small diameter pipe (maybe only half or three quarter inch dim) has been installed from the pump and that this diameter has been continued through the house.

Trying to pump water down a small pipe is like trying to wash your car with a hypodermic syringe, you can push as hard as you want but that water can only go through the pipe as fast as the pipe will allow.

In Paul’s house when water from the pump comes to the first tee junction in the pipe, probably the garden hose, all the flow of water takes the path of least resistance and heads off to the garden hose leaving little for the rest of the house.

Design of the pipework is just as important as having the right pump to supply it. If you have a pipe feeding one tap then half inch is fine (yes I know we are talking in those strange inch things). If the pipe is feeding two taps you need a three quarter inch pipe with a three quarter tee which will feed into two half inch pipes. Note that to maintain the supply the tee itself must be three quarter inch not half inch so the reduction in pipe size occurs after the water flow has been divided.

If you have four taps you will need a one inch pipe which can feed through 1 inch tees and into four separate half inch pipes.

The whole point is to start with a large flow which is progressively broken down to smaller flows to make sure each tap is getting sufficient water.

While all this might seem obvious to you and I most zebras, giraffes and satay wafters turned master plumbers somehow don’t seem to quite get it. The situation is further confused by a common belief held by many a watery tukang (and incidentally the inmates of Bali Zoo) that if you reduce the pipe size this will mysteriously increase the water pressure. It doesn’t of course. All it does is force the water pump to work harder to attempt to drive the water through the pipe.

So where does Paul start? Well the first thing is to check the bore – the pump may be struggling if the water level is deeper than say 25 metres but, as long as the pump is working well within its operational head, I suspect that modifying the pipework will solve his problem.

As for the gas water heater, this is the “demand” type of heater without a storage tank, they heat the water as you use it. These heaters need enough flow of water to carry the heat away or they will overheat and be damaged. For this reason they are designed to protect themselves by turning themselves off if the water flow is insufficient.

If you are having problems with a gas heater which keeps switching itself off then make sure that both settings are turned down to their lowest and see if this fixes the problem. If it doesn’t you might try with a larger shower outlet (to increase the water flow) or a smaller heater that requires less water flow.

Next month the British Government, on behalf of the King Canute Society of Water Management Engineers, will present a motion to the United Nations calling on the international community to join them on the beaches in their demand that the sea should recede. With a sense of renewed commitment to addressing the problems of climate change their call is very timely and must be considered as our best hope yet of saving our planet.

Phil Wilson
Opinions are those of Phil Wilson. He can be contacted through the websites at www.mrfixitbali.com or through the office on 0361 288 789.