The engineering specifications of Metals Valve’s floating ball valve series includes the selection of seat & sealing materials’ selection, flow coefficient, as well as its torque values. Metals Valve supplies soft seated floating type ball valves in cast steel, forged steel and stainless steel materials.

1. Seat material selection of floating ball valves(soft seated).

Properties	PTFE	NYLON	PEEK	PCTFE	DEVLON
Temperature ℉	-328~428	-58~248	-148~500	-328~302	-148~302
Temperature ℃	-200~220	-50~120	-100~260	-200~150	-100~150
Pressure Ratings(LB)	150~600	150~1500	150~2500	150~1500	150~1500
Hardness	58	72	88	85	78
Tensile Strength(MPa)	14~34	55.2	134	35.9	79.9
Yield Strength(MPa)	350	250	2.2	150	5.4
Specific Gravity(g/cm3)	2.17	1.02	1.44	2.12	1.14
Water Absorption(24hr %)	0.00	1.00	0.06	0.00	0.10
Water Saturation	<0.01	1.60	0.20	<0.01	3.00

Different soft seating materials can be respectively chosen in terms of specific applications: PTFE mainly for chemical & cryogenic service, NYLON for high pressure & hydrocarbon service, PEEK for high pressure & high temperature service, PCTFE for cryogenic service, DEVLON for high pressure & hydrocarbon applications.

2. Sealing materials selection

Properties	NBR	HNBR	VITON	FFKM	EPDM
Temperature ℉	-22~230	-40~302	-4~392	-4~620	-58~302
Temperature ℃	-30~110	-40~150	-20~200	-20~327	-50~150
Specific Density(g/cm3)	1.31	1.34	1.85	2.00	0.87
Hardness(shore A)	75	75	75	75	75

Generally, all body/ bonnet seals are furnished in graphite. The sealing materials listed within this table are mainly used for stem and seat O-rings.

3. Flow Coefficient(Cv) and Operating Torque of floating ball valves