A 2 PC (two-piece) cast steel floating ball valve is a quarter-turn shut-off valve with a split-body cast steel construction and a ball that moves slightly under line pressure to seal against the downstream seat. Its soft seat provides bubble-tight shutoff rated to ISO 5208 Rate A. Submit your specification to confirm size, pressure class, seat material and end connection.

Floating Ball Principle

In a floating ball valve the ball is not fixed to a trunnion. Under line pressure the ball shifts slightly and presses against the downstream seat, which energizes the seal - a self-energizing action that gives a tight shutoff. Standard floating designs seal in one direction; bidirectional sealing is provided by adding an upstream seat. This differs from a trunnion-mounted ball valve, where the ball is anchored on shafts and the seats move to the ball.

Design Standards

Basic Design	API 608/ASME B16.34/ISO 17292/API 6D
Face to Face/End to End	ASME B16.10
Flange End	ASME B16.5
Buttwelding End	ASME B16.25
Pressure-temperature Rating	ASME B16.34
Inspection and Test	API 598
Firesafe Design	API 607/API 6FA

Design features

1. Double sealing system of packing, and firesafe design
2. Stem with emergency grease injection
3. Integral anti-blowout design structure of the stem
4. Optional locking device
5. Independent limit structure design
6. Anti-static function
7. Low torque design
8.Solid ball design

General Assembly Drawing

2 PC Cast Steel Floating Soft Seated Ball Valve Drawing

Material of Construction

Part No.	Part Name	Carbon Steel	Stainless Steel	Low Temperature
1	Body Cap	ASTM A216 WCB	ASTM A351 CF8/CF8M/CF3/CF3M	ASTM A352 LCB/LCC
2	Body Nut	ASTM A194 2H	ASTM A194 8/8M	ASTM A194 4
3	Body Stud	ASTM A193 B7	ASTM A193 B8/B8M	ASTM A320 L7
4	Gasket	Graphite	Graphite	Graphite
5	Seat	PTFE/R-PTFE/NYLON/DEVLON/PEEK	PTFE/R-PTFE/NYLON/DEVLON/PEEK	PTFE/R-PTFE/NYLON/DEVLON/PEEK
6	Ball	ASTM A105+ENP	ASTM A351 CF8/CF8M/CF3/CF3M	ASTM A352 LF2+ENP
7	Anti-static Device	Stainless Steel	Stainless Steel	Stainless Steel
8	Stem	ASTM A182 F6a	ASTM A182/A276 F304/F316/304L/316L	ASTM A182 F316
9	Body	ASTM A216 WCB	ASTM A351 CF8/CF8M/CF3/CF3M	A352 LCB/LCC
10	Thrust Washer	PTFE	PTFE	PTFE
11	Packing	Flexible Graphite/PTFE	Flexible Graphite/PTFE	Flexible Graphite/PTFE
12	Gland Flange	ASTM A216 WCB	A351 CF8/CF8M	ASTM A352 LCB
13	Positioning Screw	ASTM A193 B7	ASTM A193 B8/B8M	ASTM A320 L7
14	Positioning Piece	Carbon Steel	ASTM A240 304	ASTM A240 304
15	Retainer Ring	Carbon Steel	ASTM A240 304	ASTM A240 304
16	Lock Washer	Assembly	Assembly	Assembly
17	Handle	Carbon Steel	Stainless Steel	Stainless Steel

Note: Materials listed in the table are general. When ordering, please contact SNY sales or technical team to confirm the details.

Dimension & Weight

product-969-328

CLASS 150 Full Bore

Size		D		L-RF		L-BW		H		W		Approx Weight
NPS	DN	in	mm	in	mm	in	mm	in	mm	in	mm	lb	kg
1/2	15	0.51	13	4.25	108	5.51	140	3.35	85	6.30	160	6	3
3/4	20	0.75	19	4.61	117	5.98	152	3.66	93	6.30	160	8	4
1	25	0.98	25	5.00	127	6.50	165	4.41	112	7.09	180	12	5
1½	40	1.50	38	6.50	165	7.48	190	4.92	125	9.45	240	18	8
2	50	1.93	49	7.01	178	8.50	216	4.96	126	13.78	350	25	11
3	80	2.91	74	7.99	203	11.14	283	6.46	164	15.75	400	51	23
4	100	3.94	100	9.02	229	12.01	305	7.28	185	17.72	450	87	39
6	150	5.91	150	15.51	394	17.99	457	10.63	270	11.81	300	198	90
8	200	7.91	201	17.99	457	20.51	521	14.17	360	15.75	400	309	140
10	250	9.92	252	20.98	533	22.01	559	16.14	410	15.75	400	507	230

CLASS150 Reduced Bore

Size		d		D		L-RF		L-BW		H		W		Approx Weight
NPS	DN	in	mm	in	mm	in	mm	in	mm	in	mm	in	mm	lb	kg
3/4×1/2	20×15	0.51	13	0.75	19	4.61	117	5.98	152	2.56	65	5.91	150	8	4
1×3/4	25×20	0.75	19	0.98	25	5.00	127	6.50	165	2.76	70	6.30	160	11	5
1½×1	40×25	0.98	25	1.50	38	6.50	165	7.52	191	3.15	80	7.09	180	17	8
2×1½	50×40	1.50	38	1.93	49	7.01	178	8.50	216	3.62	92	9.45	240	22	10
3×2	80×50	1.93	49	2.91	74	7.99	203	11.14	283	5.59	142	13.78	350	46	21
4×3	100×80	2.91	74	3.94	100	9.02	229	12.01	305	5.98	152	15.75	400	77	35
6×4	150×100	3.94	100	5.91	150	15.51	394	17.99	457	7.09	180	17.72	450	161	73
8×6	200×150	5.91	150	7.91	201	17.99	457	20.51	521	11.42	290	11.81	300	265	120
10×8	250×200	7.91	201	9.92	252	20.98	533	22.01	559	11.46	291	15.75	400	441	200

CLASS 300 Full Bore

Size		D		L-RF		L-BW		H		W		Approx Weight
NPS	DN	in	mm	in	mm	in	mm	in	mm	in	mm	lb	kg
1/2	15	0.51	13	5.51	140	5.51	140	3.35	85	6.30	160	7	3
3/4	20	0.75	19	5.98	152	5.98	152	3.66	93	6.30	160	9	4
1	25	0.98	25	6.50	165	6.50	165	4.41	112	7.09	180	15	7
1½	40	1.50	38	7.48	190	7.48	190	4.92	125	9.45	240	28	13
2	50	1.93	49	8.50	216	8.50	216	4.96	126	15.75	400	42	19
3	80	2.91	74	11.14	283	11.14	283	6.46	164	17.72	450	86	39
4	100	3.94	100	12.01	305	12.01	305	7.28	185	21.65	550	132	60
6	150	5.91	150	15.87	403	17.99	457	10.63	270	11.81	300	287	130
8	200	7.91	201	19.76	502	20.51	521	14.17	360	15.75	400	430	195
10	250	9.92	252	22.36	568	22.01	559	16.14	410	15.75	400	639	290

CLASS 300 Reduced Bore

Size		d		D		L-RF		L-BW		H		W		Approx Weight
NPS	DN	in	mm	in	mm	in	mm	in	mm	in	mm	in	mm	lb	kg
3/4×1/2	20×15	0.51	13	0.75	19	5.98	152	5.98	152	3.35	85	6.30	160	8	4
1×3/4	25×20	0.75	19	0.98	25	6.50	165	6.50	165	3.66	93	6.30	160	13	6
1½×1	40×25	0.98	25	1.50	38	7.48	190	7.52	191	4.41	112	7.09	180	23	11
2×1½	50×40	1.50	38	1.93	49	8.50	216	8.50	216	4.92	125	15.75	240	35	16
3×2	80×50	1.93	49	2.91	74	11.14	283	11.14	283	4.96	126	15.75	400	77	35
4×3	100×80	2.91	74	3.94	100	12.01	305	12.01	305	6.46	164	17.72	450	117	53
6×4	150×100	3.94	100	5.91	150	15.87	403	17.99	457	7.28	185	21.65	550	220	100
8×6	200×150	5.91	150	7.91	201	19.76	502	20.51	521	10.63	270	11.81	300	375	170
10×8	250×200	7.91	201	9.92	252	22.36	568	22.01	559	14.17	360	15.75	400	551	250

CLASS 600 Full Bore

Size		D		L-RF		L-BW		H		W		Approx Weight
NPS	DN	in	mm	in	mm	in	mm	in	mm	in	mm	lb	kg
1/2	15	0.51	13	6.50	165	6.50	165	3.35	85	6.30	160	11	5
3/4	20	0.75	19	7.48	190	7.48	190	3.66	93	7.09	180	18	8
1	25	0.98	25	8.50	216	8.50	216	4.41	112	9.45	240	24	11
1½	40	1.50	38	9.49	241	9.49	241	4.92	125	13.78	350	31	14
2	50	1.93	49	11.50	292	11.50	292	5.12	130	15.75	400	40	18
3	80	2.91	74	14.02	356	14.02	356	7.01	178	19.69	500	75	34
4	100	3.94	100	17.01	432	17.01	432	7.48	190	12.01	305	165	75

CLASS 600 Reduced Bore

Size		d		D		L-RF		L-BW		H		W		Approx Weight
NPS	DN	in	mm	in	mm	in	mm	in	mm	in	mm	in	mm	lb	kg
3/4×1/2	20×15	0.51	13	0.75	19	7.48	190	7.48	190	3.35	85	6.30	160	9	4
1×3/4	25×20	0.75	19	0.98	25	8.50	216	8.50	216	3.66	93	7.09	180	12	6
1½×1	40×25	0.98	25	1.50	38	9.49	241	9.49	241	4.41	112	9.45	240	23	11
2×1½	50×40	1.50	38	1.93	49	11.50	292	11.50	292	4.92	125	13.78	350	44	20
3×2	80×50	1.93	49	2.91	74	14.02	356	14.02	356	5.12	130	15.75	400	64	29
4×3	100×80	2.91	74	3.94	100	17.01	432	17.01	432	7.01	178	19.69	500	130	59
6×4	150×100	3.94	100	5.91	150	22.01	559	22.01	559	7.48	190	12.00	305	209	95

Soft Seat and Leakage Class

A soft seat uses a resilient insert against the ball surface. Common inserts are PTFE, glass-filled RPTFE, PEEK, Nylon and Devlon. Soft seats achieve bubble-tight shutoff classified as ISO 5208 Rate A when tested per API 598 or ISO 5208. Seat temperature is limited by the insert material, so the seat choice is driven by the service temperature and medium.

Seat material	Typical max. temperature	Characteristics
PTFE (virgin)	≈ 200 °C	Low friction, broad chemical resistance
RPTFE (glass-filled)	≈ 230 °C	Better stability, reduced cold flow
PEEK	≈ 260 °C	High strength, wear resistant
Nylon	≈ 120 °C	Good wear resistance for air/water
Devlon / TFM	≈ 220 °C	Improved PTFE properties
Metal seat	Higher (per trim)	Fire-safe, erosive service; ISO 5208 Rate D

Applications

Oil and gas gathering, transmission and distribution lines

Refining and petrochemical process piping

Chemical processing and injection lines

Water treatment and utility systems

HVAC and general industrial services

Power plant auxiliary and instrument lines

Suitability depends on medium, design pressure, temperature, seat material and project specification. The valve is not a universal rating for all media, pressures or temperatures, and sour-service or low-temperature duty must be stated at ordering.

Material Certificates and Delivery

Standard delivery documents include a Material Test Certificate (MTC) to EN 10204 3.1, shell and seat test records, and marking per MSS SP-25. Where the purchase order requires it, EN 10204 3.2 with third-party attestation, additional non-destructive examination, and low-temperature or sour-service verification are provided. Each valve carries a heat or serial identification for traceability. Export packaging, end protection and transport documents are arranged to the destination and schedule agreed in the order.

Valve factory

valve factory

Provide the following to receive a quotation: nominal size and pressure class, body material, seat material, end connection type, bore type, operation method, quantity, required inspection and documentation, and delivery destination with requested schedule. A drawing or data sheet helps confirm the exact configuration.

Request a Quotation

FAQ

What is a 2 PC cast steel floating ball valve?

A 2 PC cast steel floating ball valve is a quarter-turn shut-off valve with a two-piece, split-body cast steel construction and a ball that moves slightly under line pressure to load the downstream seat. The soft seat provides a bubble-tight seal rated to ISO 5208 Rate A.

How does a 2-piece valve differ from a 1-piece and 3-piece ball valve?

A 1-piece valve is a single unibody casting that is typically reduced bore and not field-repairable. A 2-piece valve splits at the ball centerline into two bolted halves, allows in-line access to seats and stem seals, and is offered in full or reduced bore. A 3-piece valve adds a separate end-cap body for the fastest trim replacement but has more joints.

What does "floating" mean in a floating ball valve?

In a floating ball valve the ball is not anchored on a shaft. Line pressure pushes the ball against the downstream seat, which energizes the seal. This self-energizing action gives a tight shutoff in one direction as standard; bidirectional sealing is available with a second upstream seat.

What is a soft seat, and what leakage class does it provide?

A soft seat uses a resilient insert such as PTFE, RPTFE, PEEK, Nylon or Devlon against the ball. It achieves bubble-tight shutoff classified as ISO 5208 Rate A when tested per API 598 or ISO 5208. Seat temperature is limited by the insert material.

Which standards apply to 2 PC cast steel floating ball valves?

Design is covered by API 608, with pressure-temperature ratings referenced to ASME B16.34, and international options under ISO 17292 and BS 5351. Face-to-face follows ASME B16.10, and testing follows API 598, ISO 5208 or EN 12266-1. The applicable edition is defined by the purchase order.

What sizes and pressure classes are available?

Typical cast steel floating ball valves cover NPS ½–10 (DN15–250) and Class 150–600 (PN16–PN100), with sizes and ratings confirmed against the ordered model and supply range. Larger sizes or higher classes are evaluated per inquiry.

What cast steel body materials are used?

The standard body is ASTM A216 WCB carbon steel. Low-temperature service uses ASTM A352 LCB or LCC, and high-temperature service uses ASTM A217 WC6 or WC9. Stainless options such as A351 CF8 or CF8M are available where the medium requires them.

What information is needed to request a quotation?

Provide the nominal size and pressure class, body material, seat material, end connection type, bore type, quantity, required inspection and documentation, and delivery destination with schedule. Drawings or a data sheet help confirm the exact configuration.

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