Plumbing Flow Rate Problem

Dec 12, 2015 33 Replies

A question on this new cistern I've just bought. How long will it take each of two pipes to fill the cistern if one of them alone takes 9 minutes longer to fill it than the other, and 25 minutes longer than the two together?


Time for some simultaneous equations I think :)

Andrew

Taking into account Bernoulli effects? :-)

So which GCSE question is this for then? These sort of stupid questions abound in such useless exams. The answer is a fish. Brian

I think you need to specify the volume of the cistern. With the info you've provided, you can only calculate the ratio of the two flow rates. The faster flow rate is 1.5625 times the slower fill rate.

BIMBW!

I suspect you are. ;-) Where's Dave Baker when you need him?

Can we have an OT: prefix on these?

Why? Carpet laying and plumbing are not OT for this group? ;->

Well the labourer at work did ask me how much laminate to buy to cover his lounge floor. He had measured the length and width of the lounge but had no idea what to do with those two measurements.

Labourer? You're really talking about your apprentice here surely?

Andy Burns scribbled

Recently, the OT posts are those dealing with DIY.

Well, I'm quite surprised NOBODY got the answer after all the insults about these questions being too easy.

The correct answers were 36 and 45 minutes.

here's a nice one for you.

You have a 10 tooth and a 40 tooth timing wheel, designed for use with a belt of 0.1 inch tooth spacing.

A 56 tooth belt is available.

How far apart will the pulley shafts be for correct (no slop) engagement of belt and pulleys?

I actually never found out how to calculate this, possibly because I found a site that did it for me ;-)

In message , Cursitor Doom writes

It's called having better things to do.

The Natural Philosopher scribbled

Does it matter, that's what adjusters are for, 'cos eventually the belt will slacken.

Yes it does, because on small belts you don't need adjusters. They are for lazy sods who cant do sums.

Oh hang on, its Jonno...

Even if it doesn't, without some means of initial adjustment, elasticity in the belt under load can make it impossible to compensate for the effects of tight and slack side tension in the belt. Most importantly the latter.

Turnip at his best, as per usual.

michael adams

...

Ah right !

Beneath a certain size the laws of mechanics, elasticity etc. don't operate.

There must be a Noble Prize in this for someone.

If only they awarded one for bullshit, that is.

formatting link

michael adams

....

The Natural Philosopher scribbled

The same Jonno who taught you everything you now know about British wine.

Join the Discussion

Have something to add? Share your thoughts — no account required.

Didn't find your answer?

Ask the community — no account required