Product name：	DY30AXSlow opening and quick closing check valve	Product model：	DY30AX
Applicable media：	Water, oil, sewage, sea water	Connection form：	flange
Applicable temperature：	0-80 ℃	Nominal diameter：	DN50-DN1000
Common materials：	Cast iron, cast steel, stainless steel	Technical consultation：	0577-67975099

 DY30AXSlow opening and slow closing check valve water supply and drainage valve is commonly used in domestic water supply, fire protection system and industrial water supply system. Used to control flow, water level, etc. Various applications and check valves. The company's (dy30ax) slow opening and slow closing check valve consists of valve body, valve cover, valve disc, valve stem, spring, pilot valve and other parts. The diaphragm cavity is between the upper valve cover and the lower valve cover, and a diaphragm is arranged in the diaphragm cavity. The diaphragm is connected with the central shaft, and the other end of the central shaft is connected with the valve, and the valve is in contact with the valve seat. The water container is connected with the inlet and outlet control holes of the upper valve cover, the outlet water of the water container and the upper valve cover is throttling connected, and the water inlet of the water container and the upper valve cover is unidirectional communication. It can be used in sewage, clean water and raw water systems without water quality requirements.

It can replace the traditional design of check valve, electric valve and water hammer absorber. Dy30ax multi-function check valve has the functions of slow opening, slow closing, water hammer and check. Its reliability and effect are better than the traditional form. The product has stable quality and is widely used in municipal construction, irrigation and water conservancy, thermal power generation, petrochemical, metallurgy and mining, fire protection and environmental protection, food, shipping, medicine and textile and other fields. Dy30bx slow opening and quick closing check valve adopts double chamber driving device and Y-type structure.

1. Slow opening process: set the opening pressure of the multi-functional check valve to P (P is generally less than the outlet pressure of the normal operation of the water pump), adjust the spring to make the X elastic force equal to P. when the water pump is just opened and the outlet pressure is lower than P, the lower plug head is closed. Although the upper plug is opened, the water in the upper chamber of the main valve cannot be discharged due to the one-way action of the small check valve, When the outlet pressure of the water pump rises to more than or equal to P, the diaphragm of the pilot valve moves upward to drive the upper and lower plug heads upward,
2. Operation process: when the water in the upper chamber of the main valve is completely drained, the main valve is fully opened. The multifunctional check valve, which is carried in the upper chamber and communicated with the back of the valve, has the characteristics of small water loss and energy saving.  
3. Slow closing process: the water pump stops running, and the main valve is closed by two poles. First, it closes 90% quickly and then slowly, so as to remove the water hammer
The main parts of dy30ax slow opening and slow closing multi-functional check valve are as follows

Part name	texture of material
Valve body and cover	Cast iron, cast steel, stainless steel
Stem	Chromium stainless steel
Disc	Carbon steel, stainless steel + nitrile rubber
	Nitrile rubber
Spring spring	stainless steel

塞头关闭,塞头开启,主阀上腔水开始排出主阀缓慢打开。 

DN	L	H	D			D1			n-d
			1.0MPa	1.6MPa	2.5MPa	1.0MPa	1.6MPa	2.5MPa	1.0MPa	1.6MPa	2.5MPa
50	203	293	165	165	165	125	125	125	4-18	4-18	4-18
65	216	328	185	185	185	145	145	145	4-18	4-18	8-18
80	248	364	200	200	200	160	160	160	8-18	8-18	8-18
100	283	418	220	220	235	180	180	190	8-18	8-18	8-22
125	330	481	250	250	270	210	210	220	8-18	8-18	8-22
150	356	543	285	285	300	240	240	250	8-22	8-22	8-26
200	450	673	340	340	360	295	295	310	8-22	12-22	8-26
250	540	792	395	405	425	350	355	370	12-22	12-26	12-26
300	570	927	445	460	485	400	410	430	12-22	12-26	12-30
350	635	957	505	520	555	460	470	490	16-22	16-26	16-30
400	700	1188	565	580	620	515	525	550	16-26	16-30	16-33
450	770	1218	615	640	670	565	585	600	20-26	20-30	16-36
500	810	1256	670	715	730	620	650	660	20-26	20-33	20-36
600	900	1600	780	840		725	770		20-33	20-36	20-36
700	980	1750	895	910		840	840		24-30	24-36
800	1120	1900	1015	1025		950	950		24-33	24-39
900	1280	2100	1115			1050			28-33
1000	1320	2400	1230			1160			28-36