Advanced hardening technology employed for ball and seat
Metal to metal sealed design has been employed perfectly for the ball and seat, which has also adopted the advanced hardening technologies, such as uItro-sonic spray coating, nickel base spray weldling, surface specially hardening, stellite spray welding, ceramic material with high strength and hardness, and so on. Surface hardness of the ball and seat may generally reach more than HRC60, Maximun is up to HRC74, and application temperature of the material may be up to 540℃, Maximun is 980℃. Combining strength of the material gets to more than 10000 PSI. Besides, the surface materials posses also very good resistance properties of friction and impact. Metal to metal sealed ball valves made by HANGDA are suitable for use in most criticle working conditions.

Valve stuck under high temperature prevented
In the case of high temperature working condition, the valve seat and ball would easily get stuck due to heat expansion, and the valve could not be open. Metal to metal sealed ball vaIves made by HANGDA employ the patented design of bevelling spring loading, which would absorb the heat expansion of parts caused by the bevelling spring. So, it is ensured that the valve would not get stuck and be open and close easily in the case of high temperature condition.

An entire fire safe structure
The metal to metal sealed structure has been adopted for the valve sealing surface design. Packing is so designed with graphite, and gasket is so designed with stainless steel, plus graphite that the valve can assure reliable tightness even if under fire condition.

Excellent tightness function
A unique technique has been employed for the ball grinding, which makes the ball surface reach
extreme round and smooth by rotating the ball and grinding apparatus at different directions in space. The tightness function of the valve meets completely and exceeds the standard requirement.

Natural anti-atatic structure
Metal to metal sealed ball valve with its body seat, ball, other metal parts, and so forth, closely contact with each other, having naturally formed a static electricity passage. In this respect, there is no need to provide special anti-static device.

Double-block and bleed function
HANGDA's metal to metal sealed trunnion ball valve is in general of the front ball sealing structure. Actually, two seats of the metal to metal sealed trunnion ball valve can both cut off separately the medium at inlet and outlet to realize double-block function. When the valve is closed, the body cavity and both the bore ends can be blocked with each other even if both ends of
the valve are under pressure at the same time, whereas the medium left in the body cavity may relieve through the relief valve.

Typical drawing and parts composition

Parts and material list

Parts NO.	Parts name	Materials
		WCB/13Cr	WCB/304	WCB/316	CF8	CF8M
1	Body	ASTM A216 WCB	ASTM A216 WCB	ASTM A216 WCB	ASTM A315 CFB	ASTM A315 CFBM
2	Packing	Graohite	Graohite	Graohite	Graohite	Graohite
3	Gland	ASTM A182 F6a	ASTM A182 F340	ASTM A182 F316	ASTM A182 F304	ASTM A182 F316
4	Gland flange	ASTM A216 WCB	ASTM A216 WCB	ASTM A216 WCB	ASTM A315 CFB	ASTM A315 CFBM
5	Gland bolt	ASTM A193 B7	ASTM A193 B7	ASTM A193 B7	ASTM A193 B8	ASTM A193 B8M
6	Circlip	Carbon steel	Carbon steel	Carbon steel	Stainless steel	Stainless steel
7	Stop collar	Carbon steel	Carbon steel	Carbon steel	Stainless steel	Stainless steel
8	Lever	Carbon steel	Carbon steels	Carbon steel	Carbon steel	Carbon steel
9	Circlip	Carbon steel	Carbon steel	Carbon steel	Carbon steel	Carbon steel
10	Thrust washer	304 Sheet+Graphite	304 Sheet+Graphite	316 Sheet+Graphite	304 Sheet+Graphite	316 Sheet+Graphite
11	Stem	ASTM A182 F6a	ASTM A182 F340	ASTM A182 F316	ASTM A182 F304	ASTM A182 F316
12	Seat seal	Graohite	Graohite	Graohite	Graohite	Graohite
13	Seat	ASTM A182 F6a+WC-Co	ASTM A182 F304+WC-Co	ASTM A182 F316+WC-Co	ASTM A182 F304+WC-Co	ASTM A182 F316+WC-Co
14	Ball	ASTM A182 F6a+WC-Co	ASTM A182 F304+WC-Co	ASTM A182 F316+WC-Co	ASTM A182 F304+WC-Co	ASTM A182 F316+WC-Co
15	Seat seal gland	ASTM A182 F6a	ASTM A182 F340	ASTM A182 F316	ASTM A182 F304	ASTM A182 F316
16	Spring	inconel750	inconel750	inconel750	inconel750	inconel750
17	Gsaket	304 Sheet+Graphite	304 Sheet+Graphite	316 Sheet+Graphite	304 Sheet+Graphite	316 Sheet+Graphite
18	Clasure	ASTM A216 WCB	ASTM A216 WCB	ASTM A216 WCB	ASTM A351 WCB	ASTM A351 WCB
19	Body bolting	ASTM A193 B7	ASTM A193 B7	ASTM A193 B7	ASTM A193 B8	ASTM A193 B8M
20	Body nut	ASTM A194 2H	ASTM A194 2H	ASTM A194 2H	ASTM A194 8	ASTM A194 8M

Note: The chart above only lists out some common composition of steel ball valve parts. We may provide other different parts material composition according to the customer's request or the actual valve working condition.

Forged steel metal to metal sealed floating ball valve
HANGDA's metal to metal sealed floating ball valve is of behind ball sealing structure, employing in general single direction tightness. The flow direction is indicatd on the valve body. If specially required by customers, HANGDA's patent of bi-direction sealing design may be selected.

Typical drawing of metal to metal sealed trunnion ball valve and parts composition

Main sizes and weights
Refer to that of floating ball valve for main dimensions and weights of metal to metal sealed floating ball valve. The flange dimensions and face to face dimensions are the same as that of floating ball valve.

Forged steel metal to metal sealed floating ball valve
HANGDA's metal to metal sealed floating ball valve is in general employing casted steel valve body. If required by customers, forged steel valve body is also available. of which the flange dimensions and face to face dimensions are the same as that of cast steel ball valve.

Main sizes and weights
Refer to that of trunnion ball valve for main sizes and weights of metal to metal sealed trunnion ball valve, of which the flange dimensions and face to face dimensions are the same as that of trunnion ball valve.

Forged steel metal to metal sealed trunnion ball valve
HANGDA company's metal to metal sealed trunnion ball valve is in general employing casted steel valve body.As per customers' requirement, forged steel valve body is also available, of which the flange dimensions and face to face dimensions are the same as that of cast steel trunnion ball valve.