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705XModel JD745X multi-function pump control valve (also known as JD745X control valve) is a dual chamber control diaphragm hydraulic operation mode, installed in the water supply and drainage system water Beijing outlet. The slow opening and quick closing pump control valve is mainly used for slow opening, quick check and slow closing. Ensure that the water pump starts quickly under low pressure. When the pump is stopped, the valve senses the change of water flow rate, quickly closes 90% and slowly closes 10%, so as to reduce water hammer and protect pipeline and pump. A filter must be installed in front of the valve.

Pressure rating: PN10, PN16, PN25
High working pressure: 1.0MPa, 1.6Mpa, 2.5MPa
Test pressure: 1.1MPa, 1.76Mpa, 2.75mpa
Body pressure: 1.5MPa, 2.4Mpa, 3.75mpa

 

Nominal size DN	L			W	H	H1	D			D1			n-d
	PN10	PN16	PN25				PN10	PN16	PN25	PN10	PN16	PN25	PN10	PN16	PN25
100	360		360	275	427.5	275.5	220	220	235	180	180	190	8-φ19	8-φ19	8-φ23
150	455		455	380	553	393	285	285	300	240	240	250	8-φ23	8-φ23	8-φ28
200	585	587	585	500	695	464	340	340	360	295	295	310	8-φ23	12-φ23	12-φ28
250	790	790	790	612	832	548	395	405	425	350	355	370	12-φ23	12-φ28	12-φ31
300	900		900	719	963	653	445	460	485	400	410	430	12-φ23	12-φ28	16-φ31
400	962	962	962	835	1116	762	565	580	620	515	525	550	16-φ28	16-φ31	16-φ37
500	1076		1076	1035	1395	975	670	715	730	620	650	660	20-φ28	20-φ34	20-φ37
600	1232			1232	1665	1174	780	840		725	770		20-φ31	20-φ37
700	1437			1257	1915	1349	895	910		840	840		20-φ31	24-φ37
800	1750			1437	2190	1543	1015	1025		950	950		20-φ34	24-φ40

Figure a: after the water pump is started, the lower control chamber is filled with water from the inlet to the lower control chamber, which pushes the valve core to move upward. The water in the upper control chamber is discharged to the outlet through the needle valve. Due to the throttling effect of the needle valve nv1, the valve is opened slowly, and the needle valve can be adjusted according to the situation to meet the needs of closing and starting.	Figure B: the valve continues to open to full open after normal operation of the pump.	Figure C: valve fully open

Fig. D: after the water pump stops, the valve disc is quickly closed to 90% under the action of induction spring and water flow, which is blocked by the nut on the valve stem to reduce the backflow water hammer, and the shrinkage port is reserved to discharge the vacuum water hammer.	Figure e: the high-pressure water at the outlet enters the upper control chamber through the needle valve nv2, and the water from the lower control chamber flows into the inlet through bv. The needle valve can adjust the slow closing time to reduce the ice hammer. The valve is gradually closed to the initial state, waiting for the next pump start-up.

 

Water flow direction
CV check valve
NV needle valve
Bv ball valve