Sealed Reliable Pressure Balanced Inverted Lubricated Oil Sealed Plug Valve for Petroleum Chemical Pharmaceutical Industries

Specification

TIANYU Back Pressure Balanced Lubricated Plug Valve: High-End Industrial Fluid Control Solution

I. Product Overview

TIANYU back pressure balanced lubricated plug valves are designed to strict API 599 and API 6D standards, integrating an inverted pressure balancing structure with a forced lubrication system for low-torque operation and bi-directional sealing under high-pressure conditions. Constructed with WCB cast steel or 304/316 stainless steel, these valves operate in media environments from -29℃ to 80℃, widely applied in rigorous fluid control scenarios across petrochemical, pharmaceutical, and power industries.

II. Key Attribute Parameters

Technical Specifications
- Bore Range: DN25~DN350 (1″~14″)
- Pressure Classes: Class 150~Class 900 (PN16~PN150)
- Temperature Range: -29℃~80℃ (standard), customizable to -40℃~180℃
- Design Standards: API 599, API 6D; Flange Standards ASME B16.5; Face-to-Face Dimensions ASME B16.10
- Testing Standard: API 598 (shell strength and seal testing)
Material Configuration
- Body/Bonnet: ASTM A216 WCB (cast steel), ASTM A351 CF8/CF8M (stainless steel)
- Plug: ASTM A182 F6a (forged stainless steel), surface hardened (HV≥250)
- Sealing System: Metal hard seal + PTFE auxiliary seal, lubrication passage in brass
- Actuators: Manual (wrench/handwheel), worm gear, pneumatic, electric (optional)
Performance Parameters
- Shell Test Pressure: 3.0/7.5/15.0/22.5MPa for Class 150/300/600/900
- Seal Test Pressure: 2.2/5.5/11.0/16.5MPa (bi-directional zero leakage, API 598 Class VI)
- Operating Torque: ≤120N·m for DN100 Class 150 valve (manual operation)

Product Overview

III. Structural Design & Technical Features

Back Pressure Balanced Structure
- A balancing piston at the plug base counteracts axial load using medium pressure, reducing operating torque by 40%~60% and resolving jamming issues in high-pressure applications. The balancing chamber connects to the medium channel, automatically compensating for pressure fluctuations to ensure stable operation in Class 900 systems.
Forced Lubrication Sealing System
- A circular lubrication groove between the body and plug injects NLGI 2# lithium-based grease via a high-pressure grease valve, forming a dynamic sealing film (sealing specific pressure ≥12MPa) while minimizing friction wear. The grease isolates media from metal surfaces, preventing scaling and corrosion to extend valve life to 8~10 years.
Bi-Directional Flow & Non-Directional Design
- Symmetric flow path eliminates the need to distinguish media direction, offering installation flexibility for bi-directional shut-off scenarios like heat exchanger inlets/outlets and tank connecting pipes. Both flow directions meet API 598 Class VI sealing standards with leakage rate ≤1×10⁻⁹m³/s.

IV. Manufacturing Processes & Quality Control

Core Technologies
- Body Casting: Investment casting (lost-wax process) ensures dimensional accuracy CT6 and surface roughness Ra≤12.5μm, with critical areas ultrasonically tested (UT) for no shrinkage defects.
- Plug Machining: CNC lathe precision turning followed by grinding polishes sealing surfaces to flatness ≤0.01mm, with fit clearance to body controlled at 0.05~0.1mm for high-pressure sealing compliance.
- Surface Treatment: Stainless steel components passivated; cast steel parts coated with epoxy resin (thickness ≥100μm), passing 1000-hour salt spray test for marine environments.
Quality Certification System
- Certifications: ISO 9001, CE (PED 2014/68/EU), API 6D (optional)
- Testing Procedures:
  - 100% shell strength test (1.5× rated pressure, 5-min hold)
  - Bi-directional seal test (1.1× rated pressure, 15-min hold)
  - Torque fluctuation test (≤15% deviation at ambient temperature)

Valve Details

V. Core Product Advantages

Advantage Dimension	Technical Details & Application Value
High-Pressure Sealing Reliability	Back pressure balance + lubrication design enables 100,000 leak-free cycles in Class 600 systems, tripling service life compared to traditional plug valves.
Low Maintenance Cost	Online grease replenishment eliminates disassembly, reducing maintenance time by 70% and downtime losses by 50%.
Corrosion Resistance	316 stainless steel suits chloride-containing media (e.g., seawater, chemical waste) with corrosion rate ≤0.01mm/year.
Operation Convenience	Manual torque is 30% lower than similar products; DN200 valves feature force-saving handwheel mechanisms for single-person operation.
Total Life Cycle Cost	≥80,000 cycles (API 598 standard) with 40% lower comprehensive cost than ball valves, ideal for long-term continuous operation.

Application

VI. Application Fields & Scenarios

Oil & Gas Industry
- Wellhead equipment, gathering pipelines (Class 300~Class 900): Resists oil-gas erosion, bi-directional sealing prevents blowout risks;
- LNG storage tank inlets/outlets: Maintains sealing reliability at -29℃ for liquefied natural gas transportation.
Chemical & Pharmaceutical Industries
- Reactor feed control: Withstands acid-base media (pH 2~12), 316L stainless steel meets FDA certification;
- Pharmaceutical clean pipelines: Inner wall polished (Ra≤0.8μm), food-grade grease formula complies with cGMP standards.
Power & Energy Sector
- Turbine lubrication oil systems: Prevents oil leakage and contamination for generator safety;
- High-pressure steam pipelines (≤16.5MPa): Erosion-resistant design outlasts gate valves by 2~3 times.
Municipal & Environmental Engineering
- High-pressure water transmission (e.g., long-distance water projects): Reduces head loss with flow resistance coefficient ≤0.8;
- Wastewater treatment sludge pipelines: Lubrication system prevents fibrous debris jamming, reducing maintenance frequency by 60%.