DOUBLE JACKSCREW SINGLE CHAIN CLAMP 10-36

Double Jackscrew Single Chain Clamp 10"–36" — Heavy-Duty Pipe Alignment and Reforming

When the job demands precise pipe alignment and serious reforming capability across a wide range of pipe diameters, the Double Jackscrew Single Chain Clamp is the professional's choice. Designed for pipe diameters from 10 to 36 inches (254–914mm), this heavy-duty chain clamp aligns all pipe wall schedules accurately, reforms pipe to Schedule 40 and delivers the kind of adaptability across fittings, elbows and tees that cage clamps simply cannot match. One chain clamp replaces the range of eight cage clamps — making it one of the most cost-effective investments in a pipe fabrication or construction toolkit.

Double Jackscrew Design for Precision Hi-Lo Elimination

The core advantage of the double jackscrew configuration is its ability to exert independent reforming pressure on both sides of the weld joint simultaneously. Each jackbar carries two jackscrews with independently pivoting pads, allowing the operator to precisely address Hi-Lo misalignment on either side of the joint — eliminating high points and achieving a flush, accurately aligned weld preparation regardless of pipe condition or wall irregularities. This capability is critical for code-quality welds in pipeline, structural and pressure vessel applications where Hi-Lo tolerances are tightly controlled.

Reform and Align Without Removing the Clamp

Unlike cage clamps that must be removed before completing the weld, the Double Jackscrew Single Chain Clamp's jackbar design provides extra clearance around the weld joint — allowing the full weld to be completed with the clamp in place. This eliminates the risk of joint movement between tack and full weld passes, improves weld consistency and significantly reduces cycle time on production pipeline and fabrication work.

One Clamp, Eight Cage Clamp Ranges

A single chain clamp covers the full pipe range of eight cage clamps, from 10 to 36 inches. This dramatically reduces the capital investment and equipment inventory required for contractors and fabrication shops working across variable pipe sizes — and simplifies tool management on complex multi-diameter projects.

High-Strength Cast Steel Alloy Jackbars

Jackbars are cast from high-quality steel alloys for maximum strength and long service life, even in the most arduous reforming applications. Additional jackbars can be added to the clamp when extra reforming pressure is required, making the system scalable to the demands of the job.

Fitting Alignment Device for Elbows, Tees and Fittings

The included Fitting Alignment Device extends the clamp's capability beyond straight pipe-to-pipe joints — allowing elbows, tees, flanges and other fittings to be accurately aligned, supported and held securely in position during the welding process. This versatility makes it a genuine all-in-one alignment solution for complex pipeline fabrication and site work.

Level and Support Device Included

The 10–36" size range comes supplied with a Level and Support Device, allowing pipe, fittings and flanges to be held safely and securely in position throughout the alignment and welding process — reducing the need for additional supports and improving safety on the job.

What's Included

• Chain (length required for the pipe range)
• Extra heavy-duty double jackscrew jackbars
• Main block(s)
• Two fine adjustments
• Fitting Alignment Device
• Level and Support Device
• Jackscrew wrench
• Operating instructions and manual
• Metal storage box

Key Specifications

Industry Applications

The Double Jackscrew Single Chain Clamp is essential equipment for oil and gas pipeline construction, shipbuilding, petrochemical and refinery fabrication, structural and pressure vessel fabrication, and site pipe fabrication across construction and infrastructure projects.

Frequently Asked Questions:

What is a Double Jackscrew Single Chain Clamp? A Double Jackscrew Single Chain Clamp is a heavy-duty pipe alignment and reforming tool that uses a chain to encircle the pipe and jackbars with dual jackscrews to apply precision reforming pressure on both sides of a weld joint. It is used to eliminate Hi-Lo misalignment, reform out-of-round pipe and align fittings for welding across a wide range of pipe diameters.

What pipe sizes does the 10"–36" Double Jackscrew Chain Clamp fit? This clamp fits pipe diameters from 10 inches to 36 inches (254mm to 914mm), covering the equivalent range of eight cage clamps in a single tool.

What is the difference between a single chain clamp and a double chain clamp? A single chain clamp uses one chain to encircle the pipe and is well suited to alignment and light reforming. A double chain clamp uses two chains, providing greater reforming force and the ability to reform heavier wall pipe. The "double jackscrew" in this clamp's name refers to the two jackscrews per jackbar — not the number of chains — meaning each jackbar can independently address Hi-Lo on both sides of the joint simultaneously.

Can I weld with the chain clamp still in place? Yes. The Double Jackscrew Single Chain Clamp is specifically designed so that the jackbar provides clearance around the weld joint, allowing the full weld to be completed without removing the clamp — eliminating joint movement risk between tack and completion passes.

What pipe wall schedules can the Double Jackscrew Chain Clamp reform and align? This clamp reforms pipe to Schedule 40 and aligns all pipe wall schedules including Schedule 80, based on pipe with a tensile strength of 45,000 psi.

Can the Double Jackscrew Chain Clamp be used for elbows and tees? Yes. The included Fitting Alignment Device allows elbows, tees, flanges and other pipe fittings to be accurately aligned, supported and secured for welding — applications that cage clamps are generally unable to accommodate.

Is the Double Jackscrew Chain Clamp available in stainless steel? Yes — a stainless steel version is available for use on stainless steel, duplex or specialty alloy pipe applications where carbon steel jackbars would cause contamination. Please contact QWS for stainless steel variant availability.