Explore our flagship precision-machined forged flanges, stub ends, expansion joints, and blind assemblies crafted for high-integrity pipeline installations globally.
In high-pressure piping systems, thermal cycling, aggressive fluid media, and bolt load relaxation can fuse gasket materials to flange faces. Flange Jack Screws (also referred to as jacking bolts, collar flange separators, or push-out bolts) represent the primary mechanical mechanism utilized by turnaround maintenance crews to break stubborn flange seals safely without damaging raised face serrations or RTJ grooves.
The mechanical force required to separate stuck pipe flanges involves overcoming the residual gasket adhesion stress ($\tau_{gasket}$) and flange face friction ($\mu_{face}$). The theoretical jacking force ($F_{jack}$) delivered per screw is governed by the thread torque equation:
$$F_{jack} = \frac{2 \cdot T_{applied}}{d_m \left( \frac{\tan\lambda + \mu}{\sec\alpha - \mu\tan\lambda} \right) + d_c \mu_c}$$
Where $T_{applied}$ is input torque, $d_m$ is mean thread diameter, $\mu$ is thread friction coefficient, and $\alpha$ is thread flank angle. Precision threading ensures up to 88% mechanical efficiency during separation.
When selecting a China Flange Jack Screw Manufacturer, precise pitch consistency and micro-finished bearing tips are vital to prevent galling against the opposing flange face during high-torque actuation.
Flange jack screws operate under severe combined bending, shear, and torsional loads during field maintenance. Our metallurgical formulations are engineered to meet strict international standards:
| Material Grade | Tensile Strength (Min. MPa) | Yield Strength (Min. MPa) | Service Temp. Range | Recommended Industrial Application |
|---|---|---|---|---|
| ASTM A193 Grade B7 | 860 MPa | 725 MPa | -29°C to +425°C | Standard Petrochemical & Oil Refinery Piping |
| ASTM A193 Grade B16 | 860 MPa | 725 MPa | -29°C to +538°C | High-Temperature Power Generation Steam Lines |
| Stainless Steel 316L | 485 MPa | 170 MPa | -196°C to +400°C | Chemical Processing & LNG Cryogenic Terminals |
| Super Duplex UNS S32750 | 750 MPa | 550 MPa | -50°C to +300°C | Subsea Manifolds & Sour Gas Offshore Platforms |
| Inconel 718 (UNS N07718) | 1240 MPa | 1030 MPa | -253°C to +650°C | Ultra-High Pressure Offshore Wellheads & Aerospace |
As global processing plants transition toward automated maintenance, digital twin asset management, and net-zero carbon footprints, flange connection component technology is evolving rapidly. China's leading forging cluster is pioneering advanced smart separation mechanisms.
Integration of piezoresistive micro-sensors directly into the jack screw core. Maintenance technicians receive real-time digital feedback on torque-to-thrust conversion ratios via wireless Bluetooth handheld readers, eliminating flange warping caused by uneven push-out forces.
Replacement of traditional molybdenum disulfide sprays with Plasma Physical Vapor Deposition (PVD) TiAlN/DLC multi-layered nanocomposite films. Reduces thread friction to $\mu \le 0.04$ while offering extreme scratch resistance during 1,000+ duty cycles.
Direct integration of green hydrogen electric arc furnace (EAF) steel billets into precision ring rolling and hot die forging facilities in Shanxi. 100% reduction in Scope 1 and Scope 2 carbon emissions across the entire flange jack screw supply chain.
According to recent mechanical maintenance surveys across Middle Eastern petrochemical refineries, premature flange face damage during gasket replacement accounts for 34% of unplanned turn-around delays. Deploying precision-engineered China Flange Jack Screws with controlled tip radii reduces flange refacing costs by over $180,000 per overhaul cycle.
Flange jack screws are engineered for critical separation operations where standard wedge tools or hydraulic splitters cannot operate due to space constraints or high explosion risks.
In high-pressure hydrocracker and coker units, hydrocarbon residue bakes gaskets onto ASME B16.5 Class 1500 flanges. Our heavy-duty jack screws deliver smooth, controlled linear push force without creating sparks, maintaining strict ATEX explosion safety standards.
Subsea oil and gas jumpers subjected to cyclic hydrostatic pressure require Super Duplex UNS S32750 jack screws. These components resist marine biofouling and pitting corrosion during long-term immersion before ROV-operated dismantling.
Main steam isolations require heat-treated ASTM A193 Grade B16 jack screws capable of enduring continuous exposure to 538°C superheated steam without experiencing stress relaxation or thermal thread seizure.
Based in Dingxiang, Shanxi — the internationally recognized center for industrial forging excellence — our facility integrates raw billet forging, multi-axis CNC thread rolling, automated heat treatment, and digital quality control under one roof.
Unlike trading entities that outsource machining, our factory manages the complete metallurgy life cycle. We maintain long-term direct procurement contracts with top steel mills (such as Baosteel and Taiyuan Iron & Steel Group), storing over 5,000 tons of certified alloy and stainless billets in stock.
Machined cut threads create microscopic shear tears that induce stress concentrations and thread galling. We utilize high-tonnage cold thread rolling machinery to form threads with cold-worked grain structures:
Spectro-chemical verification & UT flaw detection.
Controlled closed-die forging & grain alignment.
Cold thread rolling for maximum fatigue strength.
Optical & dimensional EN 10204 3.1 validation.
Engineering Procurement Construction (EPC) contractors and global industrial stockists require scalable OEM manufacturing capabilities that mitigate Total Cost of Ownership (TCO) risks while ensuring uncompromised project schedules.
By standardizing forged blank inventories for standard ASME B16.5 flange sizes ($1/2''$ to $60''$), we reduce standard export order production lead times from 45 days down to 12-15 days, providing vital support for tight refinery shutdown schedules.
Every jack screw and flange assembly can be laser-engraved with custom heat numbers, batch codes, part numbers, and client logos to facilitate fast warehouse cataloging and job-site traceability.
Heavy steel components undergo automated rust-inhibiting dipping and vacuum plastic sealing before being packed into ISPM-15 compliant fumigation-free reinforced plywood cases with custom internal dividers.
Navigating global pressure vessel directives requires flawless documentation. Our dedicated compliance department ensures every shipment meets destination country legal mandates and third-party inspection criteria.
Our manufacturing and quality assurance frameworks align seamlessly with major global standards organizations:
We work regularly with internationally recognized independent inspection agencies including SGS, TÜV Rheinland, Bureau Veritas (BV), DNV GL, and Lloyd's Register. Every shipment includes:
Detailed engineering answers to critical technical questions asked by piping designers, turnaround managers, and procurement professionals.
The sizing of flange jack screws is determined by the pressure rating and nominal size of the flange per ASME B16.5 or EN 1092-1 specifications. Typically, jacking holes are tapped to the same thread pitch as the main flange studs or one size smaller. The required torque is calculated based on the estimated gasket adhesion force ($\tau$) plus pipe axial friction. We recommend referring to ASME PCC-1 (Guidelines for Pressure Boundary Bolted Flange Joint Assembly) or consulting our engineering desk for customized finite element analysis (FEA) assistance.
Galling is prevented through three engineering controls: 1) Radius Tip Geometry: The contact end of our jack screw is precision-machined with a smooth spherical radius rather than a sharp point, distributing point loads evenly; 2) Hardness Differential: The jack screw tip is heat-treated to maintain a controlled hardness differential relative to the flange body material; and 3) Anti-Galling Coatings: We apply dry-film Molybdenum Disulfide ($MoS_2$) or Xylan fluoropolymer coatings to ensure low friction coefficients during engagement.
Yes. In addition to standard UNC, UNF, and Metric coarse threads, our CNC machining centers are fully equipped to cut or roll custom Acme trapezoidal threads, fine pitch metric threads, and special multi-lead threads. Simply provide your PDF/DWG technical drawings or physical samples, and our engineering team will deliver a comprehensive manufacturing feasibility review within 24 hours.
Thread rolling is a cold-forming manufacturing process that burnishes thread flanks into continuous metal grain lines rather than cutting through steel fibers. This results in up to 300% higher fatigue resistance, superior tensile shear strength, enhanced thread root radius accuracy, and an ultra-smooth surface finish ($Ra \le 0.4\,\mu\text{m}$). This minimizes thread binding, galling, and thread stripping under heavy field load conditions.
Every export order ships with a comprehensive quality package, including an EN 10204 3.1 Mill Test Certificate detailing raw material heat number chemistry, tensile/yield strengths, impact test values, and heat treatment charts. Additionally, we provide NDT inspection reports (UT/MT), dimensional calibration logs, certificate of origin (CO), packing list, and commercial invoice. EN 10204 3.2 certificates witnessing third-party inspection are available upon request.
For standard carbon steel (ASTM A105 / A193 B7) flange components held in raw forged blank inventory, standard machining and shipping lead time is 7 to 15 days. For custom forged-to-order products, special duplex alloys, or heavy custom machining, typical lead times range from 20 to 35 days depending on raw material billet availability and heat treatment requirements. Expedited emergency production runs can be arranged for critical refinery turnarounds.
Browse our secondary line of specialized stub end flanges, socket weld connections, ASME B16.47 heavy industrial neck flanges, and precision plate flanges.
