D741H、D743HThe flange type hydraulic butterfly valve is suitable for the outlet pipeline of the pump with water as the medium. It is used as a closed circuit and check valve to avoid and reduce the backflow of medium and excessive water hammer in the pipeline system, so as to protect the pipeline system. Its function is to replace two valves with one valve (traditional pipeline design uses gate valve with check valve or ordinary butterfly valve with check valve), gongheng valve d741h, d743h flange hydraulic butterfly valves purchase three eccentric structure: the valve stem axis and butterfly plate sealing surface offset by a dimension a, and with the valve body passage axis offset by a dimension B, the valve seat rotation axis and the valve body channel axis form an eccentric angle A, Therefore, three eccentricities are formed. When the butterfly valve is opened from 0 to 90, the sealing surface of the butterfly plate will immediately break away from the valve seat surface at the moment of opening. When the butterfly valve is closed at 90-0, the sealing surface of the butterfly plate will contact and compress the sealing surface of the valve seat only at the moment of closing. However, the seal specific pressure can be adjusted arbitrarily by changing the external driving torque. Therefore, there is no friction between the valve seat and the sealing surface on the butterfly plate, eliminating the possibility of wear and leakage.

 支架式蝶板结构：蝶板强度高，过流面积大，流阻小。

 Torque seal: when the butterfly valve is closed due to the three eccentric structure, the sealing specific pressure between the two sealing surfaces of the sealing pair is generated by the driving torque applied to the valve stem. It can not only eliminate the decrease and disappearance of sealing specific pressure caused by the aging of elastic material, cold flow and elastic failure of conventional elastic valve seat, but also realize the arbitrary adjustment of sealing specific pressure by changing the driving torque in the outside, so as to improve the sealing performance of triple eccentric butterfly valve and greatly increase the service life of butterfly valve.

 

Soft hard laminated metal seal structure: the butterfly plate seal ring adopts the combination of soft and hard laminated stainless steel sheet and flexible graphite, which makes it have the dual advantages of metal hard seal and elastic seal, and has excellent sealing performance no matter under low and high temperature conditions.
Sealing ring: the sealing ring is clamped on the butterfly plate by pressing plate, which is easy to install, adjust and replace. The upper and lower parts of the valve stem are equipped with shaft sleeves to prevent wear and adhesion, and improve the service life.

D741H、D743HMain technical parameters of flange type hydraulic butterfly valve

Nominal diameter（mm）		1400-2400	1200-2400	500-2400	500-2400	500-1600
Nominal pressure（MPa）		0.25	0.6	1.0	1.6	2.5
Test pressure	strength test	0.375	0.9	1.5	2.4	3.75
	Sealing test	0.275	0.66	1.1	1.76	2.75
Applicable media		水
Applicable media（℃）		≤80℃
Medium velocity		3m/s

D741H、D743HMain parts materials of flange type hydraulic butterfly valve

Part name	Material Science
Valve body and butterfly plate	Gray cast iron, ductile iron, carbon steel
Valve shaft	stainless steel
seal ring
filler	NBR

 

D741H、D743HExecutive standard for flange type hydraulic butterfly valve

Manufacturing standards	JB/TB527-97、GB/T 12238-89
Flange standard	GB/T 17241.6-1998、GB2555-2556-81
Structural length standard	GB12221-89
Inspection standard	GB/T 13927-92

 

D741H、D743H-6/10/16Main dimensions of flange type hydraulic butterfly valve

DN	PN	D	D1	B	L	A	B	H
500	1.0	670	620	43	229	720	1650	1360
600	1.0	780	725	48	267	720	1730	1390
700	1.0	895	840	54	392	720	1800	1445
800	1.0	1015	950	58	318	720	1870	1485
900	1.0	1115	1050	61	330	720	2070	1865
1000	1.0	1230	1160	67	410	755	2165	1930
1200	1.0	1455	1380	65	470	905	2265	2030
1400	1.0	1675	1590	68	530	905	2665	2270
1200	0.6	1405	1340	65	470	755	2365	2025
1400	0.6	1630	1560	68	530	755	2665	2270
1600	0.6/0.25	1830	1760	68	600	905	2940	2380
1800	0.6/0.25	2045	1970	70	670	905	3325	2470
2000	0.25	2265	2180	54	760	905	3660	2370
2200	0.25	2475	2390	60	840	1123	4325	2940
2400	0.25	2685	2600	62	910	1123	4530	3000

 

1. Before installation, check whether the specification, pressure, temperature and corrosion resistance of butterfly valve meet the use requirements. Check whether the parts are damaged or loose.
2. The butterfly valve can be installed on the pipeline at any angle and should be closed; when welding the pipe flange, the valve sealing port should be blocked with a plate to prevent particles and sundries from damaging the sealing surface. After welding, take down the valve, clean the valve sealing surface and pipe cavity, and then install the fixed valve.
3. Please pay attention to the pressure bearing direction when the valve is closed.
4. Before installation, the sealing surface (sealing surface at both ends, sealing surface of butterfly plate and sealing surface of valve seat) shall be thoroughly cleaned to remove dust and dirt.
5. Before installation, the butterfly valve should be air tested, and the opening and closing position should be flexible, and the opening and closing position should be consistent with the position indicated by the pointer.
6. Manual operation, clockwise is off, counter clockwise is on, pointer indication is in place, it is not allowed to open and close the valve with additional force.
7. During the pressure test of the valve, it is not allowed to use single flange for installation and pressure test, but double flange installation and pressure test must be adopted. The test pressure shall comply with GB / T13927-92.
8. The bolts shall be tightened symmetrically and alternately instead of separately.
9. The limit screw has been adjusted before delivery, so it is not allowed to adjust it easily. If the configuration of driving device is electric or pneumatic, please refer to the manual of supporting drive device.
10. When the electric butterfly valve leaves the factory, the opening and closing stroke of the control mechanism has been adjusted. In order to prevent the wrong direction when the power supply is connected, the user should first manually open it to the half open position before connecting the power for the first time, and then press the inching switch to check that the direction of the indicator wheel is consistent with the opening direction of the valve.
11. If the valve is found to be open and closed abnormally, the cause shall be found out for repair and elimination, so as to prevent the valve from being damaged due to opening and closing by means of applying force.