The Q61F three-piece extended welding ball valve is a valve specially designed for high temperature and high pressure and harsh working conditions. It adopts a three-stage valve body structure (left valve body, right valve body, middle valve body) and extended valve stem design. It is connected to the pipe through welding to ensure seal reliability and long life. Its sphere can rotate 360° and can be quickly opened and closed by valve stem drive. It is suitable for pipeline systems that require frequent operation or permanent installation in petroleum, chemical industry, electricity and other industries. It is especially suitable for buried ground, narrow space or easy crystallization of medium.
Model analysis
Q: Represents the Ball Valve.
6: The connection method is welding (Welded).
1: The structure is straight-through (floating ball structure).
F: The sealing surface is made of polytetrafluoroethylene (PTFE) or enhanced tetrafluoro (such as RPTFE).
Core features
Three-piece split structure
Convenient maintenance: The valve body is bolted by the left, middle and right parts, and can quickly remove and replace the valve seat, ball or seal without the need to replace the valve as a whole.
High sealing: The middle valve body and the ball cooperate precisely to reduce the risk of medium leakage.
Extended valve stem design
Suitable for complex environments: valve stem lengthening (usually 30%~50% longer than standard type), suitable for buried installation, insulation layer wrapping or scenarios where operating distance is required.
Anti-leakage upgrade: The extended valve stem is sealed with multi-stage packing (such as graphite + PTFE combination) to prevent media leakage.
Full soldering connection
High pressure bearing capacity: The valve body and pipeline adopt Butt Weld or Socket Weld to eliminate the leakage point of flange connection, and the pressure can reach PN40~PN100 (Class 600~Class 2500).
Corrosion resistance: The welding structure avoids corrosion problems of bolt holes and is suitable for corrosive media such as acids, alkalis, and salts.
High temperature and high pressure resistance
Valve seat material: PTFE sealing temperature resistance is ≤200℃, it can be upgraded to PPL (para polyphenylene) or metal sealing (such as stainless steel + graphite), with a temperature resistance of 450℃.
Valve body material: carbon steel (WCB), stainless steel (CF8/CF8M), alloy steel (WC6/WC9), adapting to the temperature range -196℃~+550℃.
Low flow resistance and bidirectional sealing
Full Bore design, the flow channel and the inner diameter of the pipe are consistent with the small pressure drop, suitable for high flow velocity or viscous media.
The bidirectional sealing structure can effectively block the medium in both forward and reverse directions, meeting the system’s reverse pressure needs.
Technical parameters
Project Parameter Description
Nominal diameter DN15~DN300 (supports non-standard customization to DN600)
Nominal pressure PN16~PN100 / Class150~Class2500
Applicable temperature -196℃ ~ +550℃ (depend on material and seal type)
Valve body material: Carbon steel (WCB), stainless steel (304/316), alloy steel
Sealing material PTFE, RPTFE, PPL, metal hard seal
Connection method Butt welding (BW), socket welding (SW)
Drive mode: Manual (handle/gear box), electric, pneumatic
Application areas
Oil and gas transportation: high-pressure natural gas pipelines and refining equipment reactors in the inlet and outlet.
Chemical process: Cutoff control of highly corrosive media (such as sulfuric acid, chlor-alkali).
Power system: high-temperature steam pipelines, boiler water supply system.
Low temperature engineering: LNG storage and transportation, liquid nitrogen/liquid oxygen transport pipelines.
Municipal engineering: heating pipeline network, buried water main pipe.
Comparison with two-piece ball valve
Comparison item Three-piece ball valve (Q61F) Two-piece ball valve (Q11F)
Valve body structure: three parts left, middle and right, removable and maintenance. Integrated valve body, maintenance needs to be cut from the pipeline.
Sealing replacement No need to remove the valve, directly replace the valve seat/seal. The valve needs to be removed as a whole, and the maintenance cost is high
Higher pressure bearing capacity (up to Class 2500) General (≤Class 600)
Cost Higher (complex structure) Lower
Applicable scenarios: High voltage, high frequency maintenance, strict media Medium and low voltage, disposable installation, conventional media
Selection and installation suggestions
Key points for selection:
Sealing type: choose metal hard seal for granular media; choose PTFE+ stainless steel valve body for corrosive media.
Welding method: Butt welding (BW) for high-pressure pipelines, small diameter or low-pressure socket welding (SW).
Drive configuration: Adapt electric/pneumatic actuators (explosion-proof certification) for buried or remote control scenarios.
Welding specifications:
Before welding, the pipes and valve bevels must be cleaned to avoid impurities affecting the strength of the weld.
Argon arc welding (TIG) basement + arc welding filling is used to ensure welding quality; X-ray flaw detection is required after welding.
Maintenance requirements:
Check the valve stem packing gland regularly to prevent media leakage (it is recommended to tighten once every 6 months).
Under high temperature conditions, the metal sealed ball valve needs to be regularly injected with high temperature grease to reduce the opening and closing torque.
Special customization options
Extra-long valve stem: suitable for special installation environments such as deep wells and underground pipe corridors (extended length can be customized).
Fireproof design: The valve seat and seal are made of fireproof graphite material, meeting API 607/API 6FA standards.
Anti-static structure: A spring-conducting electrostatic device is installed between the sphere and the valve stem to avoid static accumulation (compliant with GB/T 24925).
