D343W、D343FType Ni Al Bronze hard seal butterfly valve and seawater butterfly valve are widely used in the pipeline of corrosive medium such as seawater fluid, ship and water supply and drainage.

1. Three eccentric structure: a dimension a is offset between the valve stem axis and the butterfly plate sealing surface, and a dimension B is offset with the valve body channel axis, and an eccentric angle a is formed between the valve seat rotation axis and the valve body channel axis, so the three eccentricity is 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.
2. Truss type butterfly plate structure: the butterfly plate has high strength, large flow area and small flow resistance.
3. 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.
4. 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.
5. Two way sealing: because the cone angle of the sealing surface is less than the friction angle of the sealing material, the butterfly plate can realize self-locking immediately when it is closed to the sealing position, and can withstand certain reverse pressure impact.
6. Fireproof structure: all metal structure has fire safety characteristics.
7. Sealing surface of d343h, d343y, d343y metal seal butterfly valve body: hardfacing carbide or stainless steel is used to make the sealing surface have high strength, good hardness and wear resistance, and can be opened and closed for more than 600000 times without damage.
8. 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.

D343W、D343FType Ni Al Bronze hard seal butterfly valve and seawater butterfly valve(mm)

Nominal diameter		Structural length		Dimensions										Connection size
		L		H	D343F、D343H									0.6MPa			1.0MPa
mm	inch	短	长		H1	A1	B1	H2	A2	B2	H3	A3	B3	D	D1	Z-d	D	D1	Z-d
50	2	108	150	112	350	180	200	625	245	72	530	250	255	140	110	4-14	165	125	4-18
65	2 1/2	112	170	115	370	180	200	625	245	72	530	250	255	160	130	4-14	185	145	4-18
80	3	114	180	120	380	180	200	645	245	72	565	250	255	190	150	4-18	200	160	8-18
100	4	127	190	138	420	180	200	675	355	92	600	250	255	210	170	4-18	220	180	8-18
125	5	140	200	164	460	180	200	715	355	92	640	250	255	240	200	8-18	250	210	8-18
150	6	140	210	175	555	270	280	800	355	92	705	300	315	265	225	8-18	285	240	8-22
200	8	152	230	200	760	400	425	850	250	170	775	300	315	320	280	8-18	340	295	8-22
250	10	165	250	243	830	400	425	925	250	170	945	300	315	375	335	12-18	395	350	12-22
300	12	178	270	250	895	450	560	1035	450	220	1070	300	315	440	395	12-22	445	400	12-22
350	14	190	290	280	950	450	560	1070	450	220	1140	300	315	490	445	12-22	505	460	16-22
400	16	216	310	305	1190	535	580	1190	450	220	1210	300	315	540	495	16-22	565	515	16-26
450	18	222	330	350	1255	535	580	1250	650	280	1335	575	414	595	550	16-22	615	565	20-26
500	20	229	350	380	1305	535	580	1290	650	280	1415	575	714	645	600	20-22	670	620	20-26
600	24	267	390	445	1340	570	660	1455	850	380	1605	656	810	755	705	20-26	780	725	20-30
700	28	292	430	480	1520	750	550	1585	850	380	1844	656	810	860	810	24-26	895	840	24-30
800	32	318	470	530	1710	750	550	1700	1250	380	2040	656	810	975	920	24-30	1015	950	24-33
900	36	330	510	580	1810	750	550	1865	1250	380	2255	785	863	1075	1020	24-30	1115	1050	28-33
1000	40	410	550	650	1960	900	750	2015	1250	380	2380	785	863	1175	1120	28-30	1230	1160	28-36
1200	48	470	630	760	2250	1000	925	2250	1250	380	2640	785	863	1405	1340	32-33	1455	1380	32-39
1400	56	530	710	850	2435	1000	925				2886			1630	1560	36-36	1675	1590	36-42
1600	64	600	790	1030	2780	1000	925				3156			180	1760	40-36	1915	1820	40-48
1800	72	670	870	1230	3020	1100	980				3421			2045	1970	44-39	2115	2020	44-48
2000	80	760	950	1350	3270	1100	980				3685

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. Please refer to the manual for electric 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.