| 摘要 |
Liquid flow through a conduit in a branch of a hydronic system provided with a balancing valve and, in series therewith, a metering valve to obtain a desired rate of flow in the branch is regulated by positioning immediately adjacent an accelerated-flow zone in the metering valve in the conduit a pitot having an upstream side directed upstream against a direction of flow through the conduit and a downstream side directed downstream in the flow direction. The metering valve is settable in a plurality of predetermined positions each corresponding to a respective flow cross section through the conduit. A differential pressure meter is connected to both sides of the pitot, the one of the predetermined valve positions is selected that gives a near full-range reading on the meter, and the metering valve is set in this selected one position. The pressure-differential reading on the meter is monitored and the balancing valve is adjusted to regulate flow therethrough until the read pressure corresponds to a level itself corresponding to the desired rate of flow in the branch.
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