What is a fully welded ball valve?

What is a fully welded ball valve?

What is a fully welded ball valve?

Fully welded ball valve is widely used in various fields. Its superior quality and high-performance stability are beyond the reach of ordinary cast steel ball valve. Its service life is far longer than cast steel ball valve. Fully welded ball valve is widely used in urban gas, urban heating, petrochemical, shipbuilding, steel, regulating station, power plant and other kinds of pipeline equipment. Fully welded ball valve can be operated and used reliably for a long time. It needs maintenance and is easy to install. The installation of the valve is more convenient. Fully welded ball valve is suitable for class150-class600 and pn16-pn40 pipelines, which is used to cut off or connect the medium in the pipeline. The driving mode of Fully welded ball valve is manual, worm gear, pneumatic or electric. Fully welded ball valve is generally connected by butt welding.

• Specifications of Fully welded ball valves
• Materials of Fully welded ball valves
• Standard Specification for Fully welded ball valves
• Structure features of Fully welded ball valve
• Performance of Fully welded ball valve
• Design method of Fully welded ball valve split valve body
• Technical features of Fully welded ball valve
• Application scope of Fully welded ball valve
• Dimensions of Fully Welded Ball Valve
• How to order a fully welded ball valve

Specifications

Sizes
• 2” to 56” (50 mm to 1400 mm) full, reduced and venturi bore
Pressure Classes
• ASME/ANSI Class 150 to 2500 (PN 20 to PN 420), API 2000 to 5000 psi
Operating Temperatures
• From -50° F to 375° F (-46° C to 190° C) End Connections
• Flanged, weld and weld-by-flange and more
Body Styles
• Fully welded
Standard Material
• Forged carbon steel
Optional Materials
• Seat/seal trim options include: regular, corrosionresistant and sour (NACE MR0175)
Working Environment
• – 29 ℃ ~ + 250 ℃
Application

• Petroleum, chemical, natural gas, petrochemical, coal chemical and other industries

Materials

Materials used in ball valve construction are equivalent at all manufacturing plants. However, the availability of local supplies, the need to conform to national standards and to offer various trims may necessitate some variations. In corrosive applications, valve trims may be offered using various types of alloys
and stainless steels. For more information on material specifications and properties, contact your sales representative.

Trim Materials for Standard Valves

Pressure range	ASME/ANSI Class 150 to 2500 (PN 20 to PN 420)
Temperature range	-20° F to 250° F (-29° C to 121° C)
Body	ASTM A350 Gr. LF-2(M)
End connection	ASTM A350 Gr. LF-2(M)
Ball	ASTM A694 Gr. F50(M) Chrome plated or ENP
Seat ring	AISI 1040
Seat load spring	AISI 1040
Stem seals	PTFE
Lip seals	PTFE
Seat ring insert	Nylon

Optional Trim Materials

Trim	Pressure Rating	Temperature Rating	TRIM NUMBERS
			Regular	Corrosion Resistant (NACE MR0175)
Standard	ASME/ANSI Class 150 to 2500 API 2000 to 5000	-20° F to 250° F (-29° C to 121° C) -20° F to 250° F (-29° C to 121° C)	1 2	212 213
Low-temperature	ASME/ANSI Class 150 to 2500 API 2000 to 5000	-50° F to 250° F (-46° C to 121° C) -50° F to 250° F (-46° C to 121° C)	8 –	216 217
High-temperature	ASME/ANSI Class 150 to 600	-20° F to 375° F (-29° C to 190° C)	4	222
Tefzel (Acidizing)	ASME/ANSI Class 150 to 1500 API 2000 to 5000	-20° F to 300° F (-29° C to 149° C) -20° F to 300° F (-29° C to 149° C)	140 108	214 215
Tefzel Low-temperature	ASME/ANSI Class 150 to 1500 API 2000 to 5000	-50° F to 300° F (-46° C to 149° C) -50° F to 300° F (-46° C to 149° C)	223 –	– –
Duplex (Internal) stainless steel	ASME/ANSI Class 150 to 1500	-20° F to 250° F (-29° C to 121° C)	–	276
Full duplex stainless steel	ASME/ANSI Class 150 to 1500	-50° F to 250° F (-46° C to 121°C)	–	504

Standard Specification for fully welded ball valves

Design and manufacturing standards: API 6D, API 608, BS 5351, GB / T 12237
Structural length standard: ASME B 16.10, GB / T 12221

Connection flange standard: ASME B 16.5, GB / T 9112-9124, Hg / T 20592, Hg / T 20615, JB / T 74-90, JIS b2238

Test and inspection standards: API 598, GB / T 13927, GB / T 26480, JB / t9092, ISO 5208

Replace Stem Seal
In the unlikely event of a stem seal needing replacement, it can be accomplished safely with the valve in service.
With the body cavity vented, all line pressure to the stem area also is vented. Please contact your sales representative to obtain maintenance procedures.
Safeguard Downstream Work
With the valve closed and the vent fitting open, the possibility of the line media reaching a work area is reduced.
Fire-Tested for Safety
Fully welded ball valves can be supplied to API 6FA, API 607 and ISO 10497 standards. If industry standards change or customer requirements vary from the above, please contact your sales representative.
Stem Seals
Delta seals and lip seals made of PTFE are incorporated in the upper stem area.
PTFE is a low-friction, non-deteriorating material that is not subjected to rapid decompression explosion. Most valve sizes have a provision for the sealant injection to establish a secondary seal.
Trunnion Mounted Ball Allows Low-Torque Operation
Regardless of size or pressure rating, every fully welded ball valve is trunnion mounted. High-strength forged stems are located in PTFE impregnated stainless steel bearings for smooth, accurate operations. Trunnion mounted stems absorb the thrust from line pressure, preventing excess friction between the ball and seats, so even at full rated working pressure, operating torque stays low.
Double Block-and-Bleed
Whether in the fully open or fully closed position, pressure on each side of the ball is blocked from the body cavity by the seat ring. The body cavity can then be bled down or drained through the body port. When you block-and-bleed a ball valve, the following can be accomplished:
Test Valve Integrity
When the valve body is vented, the seat seal’s integrity is verified. This test can be performed with the valve open or closed. Valve performance can also be validated by verifying valve seat seal integrity.
Secondary Seat Seal
The sealant injection system provides a fast, simple way of restoring tight shutoff if any foreign object should damage the sealing surfaces. The injection system can also be used for routine flushing of the seat ring area in services where this may be required.
Upstream Sealing
At low pressure, seat-to-ball contact is maintained by Belleville springs. At higher pressures, seat contact is reinforced by line pressure.
Automatic Internal Relief of Body Pressure
Relief of excess body cavity pressure is automatic, avoiding dangerous pressure buildup. Any pressure exceeding downstream line pressure by approximately 200 psi pushes the downstream seat away from the ball, allowing the pressure to relieve into the pipeline.
Rotating Seat Rings
The exclusive rotating seat feature is standard in the fully welded ball valve size 14” (350 mm) and larger. Both seats rotate 15 degrees each time the valve is closed, exposing a new pinch point and evenly distributing seat wear.
Distributed Seat Wear
The pinch point is the area of the seat insert that experiences an increased velocity when the valve is seated closed and unseated open. This is where the seat seal experiences the most wear, and in most valves where a leak path begins. By rotating the seat ring, the pinch point wear is distributed throughout the seat seal providing a substantial increase in seat life.
Prevents Buildup
In some services, a valve can experience harmful sediment buildup around the seat ring. This can cause the seat to stick and not seal properly. The fully welded ball valve, with exclusive rotating seat, can handle these harsher services. As the seat rotates, it will prevent any buildup or break up existing buildup.
Conventional Upstream Sealing
With the upstream pressure, the bi-directional body-toseat seal is pushed toward the front sealing face of itsretaining pocket. This creates an unbalanced pressure annulus between the body seal and the ID of the seat insert, forcing the seat insert against the ball.
Downstream Sealing
With the downstream pressure, the bi-directional bodyto-seat seal is pushed toward the back sealing face of its retaining pocket. This creates an unbalanced pressure annulus between the OD of the seat insert and the body seal diameter, also forcing the seat insert against the ball.
Materials
Materials used in ball valve construction are equivalent at all manufacturing plants. However, the availability of local supplies, the need to conform to national standards and to offer various trims may necessitate some variations. In corrosive applications, valve trims may be offered using various types of alloys and stainless steels. For more information on material specifications and properties, contact your sales representative.

Structure features of fully welded ball valve:

• 1. Fully welded ball valve has advanced valve seat: the valve seat designed with many years of ball valve manufacturing experience has low friction coefficient, small operating torque, a variety of valve seat materials, and a wide range of applications.
• 2. Anti flying structure of valve rod of Fully welded ball valve: set steps at the lower part of the valve rod, and install the valve rod from the inner part of the valve body to prevent the valve rod from flying out.
• 3. Anti static function of Fully welded ball valve: the anti-static spring is set between the ball and the valve body or the valve rod, which can lead out the static electricity generated during the switching process.
• 4. Fire resistant structure of Fully welded ball valve: advanced fire resistant design. After the fire, each leakage part is designed as flexible graphite filler or stainless steel with graphite, meeting the fire resistance requirements.
• 5. When fully welded ball valve handle is operated: flat head valve rod is used, and the connection with the handle will not be misplaced, so as to ensure that the switch state indicated by the handle is consistent with that of the valve. In order to prevent the valve switch from misoperation, a locking hole is set at the fully open position to ensure that the valve is in the correct position. A kind of
• 6. The fully welded ball valve adopts the most advanced support plate structure at home and abroad, which improves the service life of the valve, reduces the operating torque of the valve and greatly extends the service life of the valve.

Performance of fully welded ball valve:

• 1).  It does not need maintenance, adjustment and lubrication, is easy to install, and operates reliably for a long time under low operating cost. The surface adopts spray plastic treatment technology, with beautiful luster, which has been in the leading level in China. There will be no external leakage. The valve body is welded, so the valve is light and easy to insulate. It is very simple to install the adjusting mechanism. The operating handle can be removed and installed by reversing.
• 2).  Since the valve seat is composed of carbon fiber reinforced Teflon sealing ring and disc spring, it has strong adaptability to the change of pressure and temperature, and will not produce any leakage within the range of pressure and temperature indicated.
• 3).  The machining process of the sphere is tracked and detected by an advanced computer detector, so the machining accuracy of the sphere is high.
• 4).  As the valve body material is the same as the pipe material, there will be no uneven stress, and there will be no deformation due to the earthquake and when the vehicle passes the ground, so the pipe is resistant to aging.
• 5).  Integral full welding, equal diameter and variable diameter channels, fixed ball and floating ball, double piston effect sealing system, automatic injection of sealant bearing.
• 6).  In order to prevent static electricity, steel balls and springs are installed between the valve rod and the ball and between the valve rod and the packing box respectively, which can keep the conductivity of all parts of the valve and the valve body, let the current pass through the area and release static electricity. Not only to prevent fire, but also to prevent corrosion, to achieve temporary cut-off, so that timely maintenance.
• 7).  The anti stripping function of the valve stem is because the valve stem is affected by the internal pressure of the valve, which always produces the force of disengagement, so the valve stem is designed as an anti stripping structure.
• 8).  Push the pressure to the valve rod with the low friction material thrust washer support, so that the valve rod only plays the role of transmitting torque.

Design method of fully welded ball valve split valve body:

The valve body design of the Fully welded ball valve has the tubular structure and the spherical structure, the tubular structure is double weld, the heat input in the welding process is large, the residual stress is complex, and the axial and radial deformation is large.
Spherical structure is the splicing of four welds. Now, due to the progress of technology, the left and right valve bodies are hot forged and formed, and the middle single weld can be welded and formed, reducing the input of linear energy and reducing the axial and radial deformation. The split structure is generally composed of valve body and left and right connecting bodies.
The connecting body and the valve body are connected by bolts. The thickness of the connecting flange and the connection strength of the bolts shall be designed by analogy according to the flange equivalent to the inner diameter of the valve body. The connection strength must prevent the connection relaxation caused by the pipe stress, so as to make the seal fail. The valve body is in contact with the opposite side of the connecting surface, and there is no gap between them. Fully welded ball valve manufacturers remind: the above information can only be referred to, if there is an accident, it is not responsible.

Technical features of fully welded ball valve:

• 1. The valve body structure is welded integrally without external leakage.
• 2. The valve seat is composed of PTFE sealing ring and spring, which has strong adaptability to the change of pressure and temperature, and will not produce any leakage within the scope of use.
• 3. The anti leakage structure of the valve rod. There is one PTFE self sealing gasket and one O-ring at the bottom of the valve rod. There are two O-rings and two PTFE gaskets on the bottom to ensure no leakage.
• 4. The material of valve body is the same as that of pipeline, and there will be no stress unevenness, and it will not be squeezed and deformed due to earthquake and when the vehicle passes the ground.
• 5. The valve body is light and easy to keep warm.
• 6. The directly buried ball valve can be directly buried in the ground, without building a large valve well, only a small shallow well on the ground, greatly saving construction costs and project time.
• 7. The length of the valve body and the height of the valve stem can be adjusted according to the construction and design requirements of the pipeline.
• 8. The machining accuracy of the sphere is very precise, easy to operate and free of bad interference.
• 9. There are two connection modes: welding and flange.
• 10. Operation mode: handle, gear (vertical / horizontal)
• 11. Under normal operation and use of the valve, the warranty period is 20 years.

Application scope of fully welded ball valve:

• 1. Urban gas: gas output pipeline, main line and branch supply pipeline, etc.
• 2. Central heating: output pipeline, trunk line and branch line of large heating equipment.
• 3. Heat exchanger: opening and closing of pipes and circuits.
• 4. Iron and steel plant: various fluid pipes, waste gas selective discharge pipes, gas and heat supply pipes, fuel supply pipes.
• 5. Various industrial equipment: various heat treatment pipes, various industrial gas and heat pipes.

The pressure test requirements for Fully welded ball valve before installation mainly include the following aspects:

• (1) Strength test. Water is used as the medium for strength test; high pressure cap is welded on the sleeve on both sides of the valve. After the valve is opened to 45 degree position, water is injected into the fully welded ball valve through the pressure test valve on the sleeve, and the pressure is increased to 1.5 times of the nominal pressure of the ball valve, and the pressure is maintained for 15 minutes. If there is no leakage, it is qualified.
• (2) Tightness test. The tightness test uses nitrogen as the medium; close the ball valve, inject nitrogen into the ball valve from the pressure test valve on the sleeve, the pressure rises to 1.1 times of the nominal pressure of the fully welded ball valve, the connecting hose of the middle cavity pressure relief valve is connected to the water container for testing, the insertion depth is 1cm; it is qualified if there is no bubble within 5min.

Size in. Nom	Ball Bore	Stem	RF Length	Flanged End n RTJ        Dia. Length		Dia.	Weld End n Length	C.L. to Bottom	Body Sphere	Lever Length	Diameter Handwheel for Gear	C.L. to Handwheel C.L.	Approximate Valve Weight lb
Dia.	B	Size	A	A	D1l	D2	A	C	E	L	G	H	Flange	Weld
2	2.06	1.0	7.0	7.5	6.00	2.06	11.0u	3.94	5.00	24	–	6.34	39	45
3	3.13	1.0	8.0	8.5	7.50	3.13	12.5u	5.12	6.75	24	–	7.44	62	75
4	4.06	1.5	9.0	9.5	9.00	4.06	14.0	5.94	8.50	36	–	8.43	115	100
6	6.00	1.5	15.5	16.0	11.00	6.00	18.0	7.91	11.25	–	12	10.43	200	225
8	8.00	2.0	18.0	18.5	13.50	8.00	21.5u	10.00	15.50	–	18	12.55	428	450
10	10.00	2.0	21.0	21.5	16.00	10.00	23.5u	12.12	18.50	–	18	14.54	705	650
12	12.00	3.0	24.0	24.5	19.00	12.00	26.5u	14.50	22.36	–	18	20.14	1210	1100
14	13.25	3.0	27.0	27.5	21.00	13.25	28.5*	14.64	24.00	–	18	21.16	1330	1230
16	15.25	3.0	30.0	30.5	23.50	15.25	30.5*	16.01	26.32	–	18	22.52	1650	1550
18	17.25	4.0	34.0	34.5	25.00	17.25	33.5*	19.25	29.20	–	24	26.19	2325	2200
20	19.25	4.0	36.0	36.5	27.50	19.25	35.5*	20.81	32.27	–	18	27.75	3310	2760
22	21.25	4.0	40.0	40.5	29.50	21.25	38.5*	22.28	36.00	–	18	29.22	3875	3510
24	23.25	4.0	42.0	42.5	32.00	23.25	42.0*	23.69	38.76	–	18	30.63	4620	4260
26	25.00	5.0	45.0	–	34.25	25.00	44.5*	26.49	41.75	–	24	34.34	6400	5600
28	27.00	5.0	49.0	–	36.50	27.00	47.0*	27.88	44.86	–	24	35.72	7200	6500
30	29.00	5.0	51.0	–	38.75	29.00	49.0*	29.51	47.90	–	24	37.37	9500	8800
34	32.75	5.0	58.0	–	43.75	32.75	54.5*	32.16	53.64	–	30	40.01	13500	12000
36	34.50	5.0	60.0	–	46.00	34.50	56.5*	33.76	56.83	–	36	41.60	15150	14500
40	38.50	7.5	69.0	–	50.75	38.50	65.0*	40.14	65.00	–	30	50.25	–	–
42	41.25	7.5	72.0	–	53.00	41.25	66.5*	41.78	68.60	–	42	51.89	–	–
48	46.50	7.5	80.0	–	59.50	46.50	76.0*	45.90	77.00	–	–	–	–	–
Size mm														kg
50	52	25	178	191	152	52	279u	100	127	610	–	161	18	20
80	80	25	203	216	191	80	318u	130	171	610	–	189	28	34
100	103	38	229	241	229	103	356	151	216	914	–	214	52	45
150	152	38	394	406	279	152	457	201	286	–	305	265	91	102
200	203	51	457	470	343	203	546u	254	394	–	457	319	194	204
250	254	51	533	546	406	254	597u	308	470	–	457	369	320	295
300	305	76	610	622	483	305	673u	368	568	–	457	512	549	499
350	337	76	686	699	533	337	724*	372	610	–	457	537	603	558
400	387	76	762	775	597	387	775*	407	669	–	457	572	748	703
450	438	102	864	876	635	438	851	489	742	–	610	665	1055	998
500	489	102	914	927	699	489	902	529	820	–	457	705	1501	1252
550	540	102	1016	1029	749	540	978*	566	914	–	457	742	1758	1592
600	591	102	1067	1080	813	591	1067*	602	985	–	457	778	2096	1932
650	635	127	1143	–	870	635	1130*	673	1060	–	610	872	2903	2540
700	686	127	1245	–	927	686	1194*	708	1139	–	610	907	3266	2948
750	737	127	1295	–	984	737	1245*	750	1217	–	610	949	4309	3992
850	832	127	1473	–	1111	832	1384*	817	1362	–	762	1016	6123	5443
900	876	127	1524	–	1168	876	1435*	858	1443	–	914	1057	6872	6577
1000	978	191	1753	–	1289	978	1651*	1020	1651	–	762	1276	–	–
1050	1048	191	1829	–	1346	1048	1689*	1061	1742	–	1067	1318	–	–
1200	1181	191	2032	–	1511	1181	1930*	1166	1956	–	–	–	–	–

n: Length (A) of a weld x
flanged-end valve is one half the sum of length (A) of a weld end and a flange
end of the same size and rating.

* Short pattern.

u: Length exceeds specified dimensions in API 6D/ISO 14313.

l: Dimensions of 22” (550 mm) flanges are per MSS-SP-44 and 26” (650 mm) to
42” (1050 mm) flanges are per ASME B16.47 series A.

How to order a fully welded ball valve?

• 1. Valve figure number (see chart below)
• 2. Pressure classification (ASME/ANSI 600 lb, API 3000 psi).
• 3. End and bore sizes.
• 4. Type of end connections (unequal ends can be furnished). For weld end valves, specify ID or OD, wall thickness and grade of pipe.
• 5. Type of operator.
• 6. Stem extension, if desired. Specify distance from valve centerline to center of handwheel, or top of power operator mounting flange.
• 7. Type of trim or application.

Note: Specify any desired accessories, if desired (lifting eyes, locking devices, and more). Handwheels are included with valves. Operating levers must be ordered separately. Information on special trims and API configurations are available upon request.
Specify the following when ordering another manufacturer’s power operator to fit a fully welded ball valve:

• 1. Valve size and pressure class and, if for field conversion, the present operator
• 2. Maximum differential pressure across valve during operation and any abnormal operating conditions
• 3. Speed of opening and closing, probable frequency of operation
• 4. Type operator desired (electric, hydraulic, pneumatic)
• 5. Information on operating medium. (If electric: voltage, frequency, single- or three-phase, open- or explosion-proof motor. If hydraulic or pneumatic: operating medium and pressure.)
• 6. Accessories and controls (limit switches, valving, instrumentation, tanks, pumps, etc)

Fully welded ball valves conform to one or more of the following specifications for pressure, temperature ratings and dimensions: ASME/ANSI, ISO 14313/API 6D, ISO 10423/API 6A, ISO 14723/API 6DSS, DIN, AFNOR, British standards, ISO 9000 and API Q1.

Source: China Fully Welded Ball Valve Manufacturer – Yaang Pipe Industry Co., Limited (www.steeljrv.com)

(Yaang Pipe Industry is a leading manufacturer and supplier of nickel alloy and stainless steel products, including Super Duplex Stainless Steel Flanges, Stainless Steel Flanges, Stainless Steel Pipe Fittings, Stainless Steel Pipe. Yaang products are widely used in Shipbuilding, Nuclear power, Marine engineering, Petroleum, Chemical, Mining, Sewage treatment, Natural gas and Pressure vessels and other industries.)

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