best valve bar mixer / combi flow limiting

[sm_jamieson]

I am fitting a Triton Tyne bar mixer. It was supposed to come with flow restrictors in the shower inlets, but they forgot to supply them. They keep saying they will supply them, but they never arrive. Anyway, I presume these valves are to ensure that the therm ports are controlling in a sensible range, and I'm sure this could be done better using an adjustable valve in the supply pipes. What valve is the best type to use to adjust flow in a controlled manner for this purpose ? Simon.

[O.B.]

The flow restrictors aren't valves. They typically are put in the cold feed where this is much higher pressure than the hot e.g. cold is mains fed and hot is gravity fed. I don't think a valve would be a good alternative.

[sm_jamieson]

Pressure/flow is always a funny one, since they are interdependant. Surely a valve is just an adjustable flow restrictor ? The flow restrictors they supply are like a disk with funny cog-like holes in. It looks like some super-hi-tec thing, but cannot possibly be ! They are supposed to be put in the hot and cold mixer inlets. The instructions say use them when the mixer is connected to a mains pressure system. Simon.

[WingedCat]

Do what I did when fitting exactly the same shower when faced with exactly the same problem - put two Pegler (or any half decent) gate valves in the feed pipes.

The flow restrictors are a very non-scientific way to solve the pressure differential because there could be a huge range of disparity between a mains cold and a tank fed hot. Using the gate valves allows you to match the flow from each perfectly. The idea is that when you switch the shower valve from full cold to full hot, you don't get a huge surge in flow or see it diminish to a trickle. Using gate valves, you will be able to achieve a perfect balance.

[sm_jamieson]

Thanks, yep, gate valves it will be. Aha - same model eh WingedCat ? I was wondering about these showers. They say if one supply fails, the shower will be cut off. This would be the action with a pressure equalising valve. Do these valves have thermo and pressure balancing functions ? I would expect a pressure function to react quicker than the thermo for a sudden opening of a tap etc. Could you give me some idea of the behaviour of the shower in such a circumstance ? Thanks, Simon.