A riser is controlled by two valves. In the supply an ASV-I or ASV-M is mounted. The ASV-M is a manual shut-off valve and the ASV-I is a manual presetting/balancing valve that can be used to limit the flow.
In the return an ASV differential pressure controller is mounted. There are three types of differential pressure controller: The ASV-P is a differential pressure controller with a fixed setting of 10 kPa. The ASV-PV is an adjustable differential pressure controller with a range of 5 to 25 kPa. The ASV-PV Plus is also an adjustable differential pressure controller but with a range from 20 to 40 kPa.
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