Home » Hydraulics Shop » Enerpac EAJ-Series, Aquajack Subsea Bolt Tensioners

Enerpac EAJ-Series, Aquajack Subsea Bolt Tensioners

Looking for help or a discount?

Call (800) 823-4937

Enerpac EAJ-Series Aquajack subsea bolt tensioners are hydraulic tools built to apply controlled bolt load on flanged joints below the waterline, where divers or ROVs handle make-up and break-out on pipeline, riser, and structural connections. Each tensioner is matched to a bolt diameter and thread, with a tonnage rating, a lift and lowered height, and a tensioner type that suits the joint and the working space. If you have a discontinued EAJ model number or a competing subsea tensioner you need to match, send your specs for a cross-reference.

Shop by Enerpac EAJ-Series, Aquajack Subsea Bolt Tensioners Category:

Enerpac EAJ Seal Kits

Enerpac EAJ-QFN-Series, EAJ Tensioner Quick Fastening Nuts

Item SKU: EAJ1QFN0750U10

Enerpac EAJ1QFN0750U10, EAJ1 Tensioner Quick Fastening Nut, 3/4 in. – 10 UN Thread Size

Price on request — fast quote
Item SKU: EAJ1QFNM02025

Enerpac EAJ1QFNM02025, EAJ1 Tensioner Quick Fastening Nut, M20 x 2,5 Thread Size

Price on request — fast quote
Item SKU: EAJ1SK

Enerpac EAJ1SK, Aquajack AJ1 Seal Kit

Price on request — fast quote
Item SKU: EAJ2QFN1000U08

Enerpac EAJ2QFN1000U08, EAJ2 Tensioner Quick Fastening Nut, 1 in. x 8 UN Thread Size

Price on request — fast quote
Item SKU: EAJ2QFNM02425

Enerpac EAJ2QFNM02425, EAJ2 Tensioner Quick Fastening Nut, M24 x 2,5 Thread Size

Price on request — fast quote
Item SKU: EAJ2QFNM02730

Enerpac EAJ2QFNM02730, EAJ2 Tensioner Quick Fastening Nut, M27 x 3,0 Thread Size

Price on request — fast quote
Item SKU: EAJ2QFNM03035

Enerpac EAJ2QFNM03035, EAJ2 Tensioner Quick Fastening Nut, M30 x 3,5 Thread Size

Price on request — fast quote
Item SKU: EAJ2SK

Enerpac EAJ2SK, Aquajack AJ2 Seal Kit

Price on request — fast quote
Item SKU: EAJ3LC

Enerpac EAJ3LC, Aquajack Subsea Bolt Tensioner, 1 1/4 in. – 1 3/8 in. Maximum Thread Range

Price on request — fast quote
Item SKU: EAJ5QFN1750U08

Enerpac EAJ5QFN1750U08, EAJ5 Tensioner Quick Fastening Nut, 1 3/4 in. – 8 UN Thread Size

Price on request — fast quote
Item SKU: EAJ5QFN1875U08

Enerpac EAJ5QFN1875U08, EAJ5 Tensioner Quick Fastening Nut, 1 7/8 in. – 8 UN Thread Size

Price on request — fast quote
Item SKU: EAJ5QFN2000U08

Enerpac EAJ5QFN2000U08, EAJ5 Tensioner Quick Fastening Nut, 2 in. – 8 UN Thread Size

Price on request — fast quote
Item SKU: EAJ5QFNM04545

Enerpac EAJ5QFNM04545, EAJ5 Tensioner Quick Fastening Nut, M45 x 4,5 Thread Size

Price on request — fast quote
Item SKU: EAJ5QFNM04850

Enerpac EAJ5QFNM04850, EAJ5 Tensioner Quick Fastening Nut, M48 x 5,0 Thread Size

Price on request — fast quote
Item SKU: EAJ5QFNM05250

Enerpac EAJ5QFNM05250, EAJ5 Tensioner Quick Fastening Nut, M52 x 5,0 Thread Size

Price on request — fast quote
Item SKU: EAJ5SK

Enerpac EAJ5SK, Aquajack AJ5 Seal Kit

Price on request — fast quote
Item SKU: EAJ6LC

Enerpac EAJ6LC, Aquajack Subsea Bolt Tensioner, 2 1/4 in. – 2 1/2 in. Maximum Thread Range

Price on request — fast quote
Item SKU: EAJ6QFN2250U08

Enerpac EAJ6QFN2250U08, EAJ6 Tensioner Quick Fastening Nut, 2 1/4 in. – 8 UN Thread Size

Price on request — fast quote
Item SKU: EAJ6QFN2500U08

Enerpac EAJ6QFN2500U08, EAJ6 Tensioner Quick Fastening Nut, 2 1/2 in. – 8 UN Thread Size

Price on request — fast quote
Item SKU: EAJ6QFNM05655

Enerpac EAJ6QFNM05655, EAJ6 Tensioner Quick Fastening Nut, M56 x 5,5 Thread Size

Price on request — fast quote
Item SKU: EAJ6QFNM06055

Enerpac EAJ6QFNM06055, EAJ6 Tensioner Quick Fastening Nut, M60 x 5,5 Thread Size

Price on request — fast quote
Item SKU: EAJ6QFNM06460

Enerpac EAJ6QFNM06460, EAJ6 Tensioner Quick Fastening Nut, M64 x 6,0 Thread Size

Price on request — fast quote
Item SKU: EAJ7QFN2750U08

Enerpac EAJ7QFN2750U08, EAJ7 Tensioner Quick Fastening Nut, 2 3/4 in. – 8 UN Thread Size

Price on request — fast quote
Item SKU: EAJ7QFNM06860

Enerpac EAJ7QFNM06860, EAJ7 Tensioner Quick Fastening Nut, M68 x 6,0 Thread Size

Price on request — fast quote
Item SKU: EAJ7QFNM07660

Enerpac EAJ7QFNM07660, EAJ7 Tensioner Quick Fastening Nut, M76 x 6,0 Thread Size

Price on request — fast quote
Item SKU: EAJ8QFN3500U08

Enerpac EAJ8QFN3500U08, EAJ8 Tensioner Quick Fastening Nut, 3 1/2 in. – 8 UN Thread Size

Price on request — fast quote
Item SKU: EAJ8QFNM08560

Enerpac EAJ8QFNM08560, EAJ8 Tensioner Quick Fastening Nut, M85 x 6,0 Thread Size

Price on request — fast quote
Item SKU: EAJ8SK

Enerpac EAJ8SK, Aquajack AJ8 Seal Kit

Price on request — fast quote
Item SKU: EAJ1QFNM02225

Enerpac EAJ1QFNM02225, EAJ1 Tensioner Quick Fastening Nut, M22 x 2,5 Thread Size

Price on request — fast quote
Item SKU: EAJ3QFNM03635

Enerpac EAJ3QFNM03635, EAJ3 Tensioner Quick Fastening Nut, M36 x 3,5 Thread Size

Price on request — fast quote
Item SKU: EAJ4QFN1625U08

Enerpac EAJ4QFN1625U08, EAJ4 Tensioner Quick Fastening Nut, 1 5/8 in. – 8 UN Thread Size

Price on request — fast quote
Item SKU: EAJ2QFN1125U08

Enerpac EAJ2QFN1125U08, EAJ2 Tensioner Quick Fastening Nut, 1 1/8 in. – 8 UN Thread Size

Price on request — fast quote
Item SKU: EAJ3QFNM03335

Enerpac EAJ3QFNM03335, EAJ3 Tensioner Quick Fastening Nut, M33 x 3,5 Thread Size

Price on request — fast quote
Item SKU: EAJ4LC

Enerpac EAJ4LC, Aquajack Subsea Bolt Tensioner, 1 1/2 in. – 1 5/8 in. Maximum Thread Range

Price on request — fast quote
Item SKU: EAJ4SK

Enerpac EAJ4SK, Aquajack AJ4 Seal Kit

Price on request — fast quote
Item SKU: EAJ7QFN3000U08

Enerpac EAJ7QFN3000U08, EAJ7 Tensioner Quick Fastening Nut, 3 in. – 8 UN Thread Size

Price on request — fast quote
Item SKU: EAJ8LC

Enerpac EAJ8LC, Aquajack Subsea Bolt Tensioner, 3 1/4 in. – 3 1/2 in. Maximum Thread Range

Price on request — fast quote
Item SKU: EAJ1QFN0875U09

Enerpac EAJ1QFN0875U09, EAJ1 Tensioner Quick Fastening Nut, 7/8 in. – 9 UN Thread Size

Price on request — fast quote
Item SKU: EAJ2LC

Enerpac EAJ2LC, Aquajack Subsea Bolt Tensioner, 1 in. – 1 1/8 in. Maximum Thread Range

Price on request — fast quote
Item SKU: EAJ3QFN1250U08

Enerpac EAJ3QFN1250U08, EAJ3 Tensioner Quick Fastening Nut, 1 1/4 in. – 8 UN Thread Size

Price on request — fast quote
Item SKU: EAJ3SK

Enerpac EAJ3SK, Aquajack AJ3 Seal Kit

Price on request — fast quote
Item SKU: EAJ4QFNM04245

Enerpac EAJ4QFNM04245, EAJ4 Tensioner Quick Fastening Nut, M42 x 4,5 Thread Size

Price on request — fast quote
Item SKU: EAJ5LC

Enerpac EAJ5LC, Aquajack Subsea Bolt Tensioner, 1 3/4 in. – 2 in. Maximum Thread Range

Price on request — fast quote
Item SKU: EAJ7LC

Enerpac EAJ7LC, Aquajack Subsea Bolt Tensioner, 2 3/4 in. – 3 in. Maximum Thread Range

Price on request — fast quote
Item SKU: EAJ7QFNM07260

Enerpac EAJ7QFNM07260, EAJ7 Tensioner Quick Fastening Nut, M72 x 6,0 Thread Size

Price on request — fast quote
Item SKU: EAJ8QFN3250U08

Enerpac EAJ8QFN3250U08, EAJ8 Tensioner Quick Fastening Nut, 3 1/4 in. – 8 UN Thread Size

Price on request — fast quote
Item SKU: EAJ8QFNM08060

Enerpac EAJ8QFNM08060, EAJ8 Tensioner Quick Fastening Nut, M80 x 6,0 Thread Size

Price on request — fast quote
Item SKU: EAJ8QFNM09060

Enerpac EAJ8QFNM09060, EAJ8 Tensioner Quick Fastening Nut, M90 x 6,0 Thread Size

Price on request — fast quote

How to Choose an EAJ Aquajack Subsea Bolt Tensioner

EAJ tensioners are sized to the joint, not chosen by feel. Work through these specs before ordering:

Tonnage rating — the hydraulic load the tensioner can apply; match it to the bolt load your joint specification calls for, typically with margin so the tool is not run at its ceiling.
Bolt diameter and thread — the stud size and thread form set which puller bar and seat fit; the tensioner must thread fully onto the protruding stud.
Lift and lowered height — lift covers the stud stretch and thread engagement, while lowered (closed) height has to clear surrounding structure in tight subsea pockets.
Tensioner type and seat — matched to the flange layout and the bolt circle so the tool seats square on the nut.
Working pressure — the tool, pump, hoses, and couplers all need to share the same pressure rating.

Which Bolting Tool Is Right for the Job?

EAJ tensioners load the stud by axial tension, which suits critical subsea and high-integrity flanges where the specification calls for bolt stretch. When the spec calls for torque instead, a square-drive or low-clearance tool is the better match. Compare the Enerpac HMT-Series Hydraulic Torque Wrenches for confined-space hex work, the Enerpac RSQ-Series Torque Wrenches and Square Drive Heads for square-drive applications, and Hydraulic Nut Cutters when a seized or corroded nut has to come off without damaging the stud. If you are not sure which method your joint requires, confirm against the joint specification and bolt schedule before tooling up.

Complete the System

A tensioner is one part of a working bolting package. Pair it with the right power and consumables:

Drive the tool with a high-pressure hydraulic pump or a self-contained hydraulic power unit sized to the tool's working pressure and the number of tensioners run at once.
Speed up stud make-up with Enerpac EAJ-QFN-Series Quick Fastening Nuts for faster running-down before tensioning.
Keep tools serviceable between deployments with Enerpac EAJ Seal Kits.
For torque-based work in the same toolkit, stock the matching Torque Wrench Accessories alongside Hydraulic Cylinders for jacking and alignment tasks.

Cross-Referencing an Obsolete EAJ Tensioner

Subsea tensioners stay in service for years, and model numbers, seats, and seal sizes are not always still cataloged when you need a match. A distributor since 1963, Northern Hydraulics can cross-reference a discontinued EAJ Aquajack tensioner, or a competing subsea tensioner, by bolt diameter, tonnage, and the flange detail. Send the part number, the bolt schedule, or photos of the tool and request a cross-reference.

Enerpac EAJ-Series, Aquajack Subsea Bolt Tensioners – Frequently Asked Questions

What is an Enerpac EAJ Aquajack subsea bolt tensioner?

It is a hydraulic tool that stretches a flange stud to apply a controlled bolt load underwater, so divers or ROVs can make up and break out subsea flange connections. Unlike a torque wrench, it loads the bolt by axial tension rather than rotation.

How do I size an EAJ tensioner for my joint?

Start with the bolt diameter and thread, then match the tensioner tonnage to the bolt load your joint specification calls for, usually with margin. Check that the tool's lowered height clears surrounding structure and that its lift covers the thread engagement and stud stretch. If you are unsure, send the flange detail and bolt schedule and we will confirm the fit.

What specs should I confirm before ordering?

Confirm tonnage rating, bolt diameter and thread, lift and lowered height, tensioner type and seat, and the working pressure so it stays within your pump and hose ratings. These determine which EAJ frame, puller bar, and seat you need.

Should I use a tensioner or a torque wrench?

It depends on the joint specification. Tensioners stretch the stud directly and are common on critical subsea and high-integrity flanges, while torque tools apply rotation. If your spec calls for torque, compare the Enerpac HMT-Series Hydraulic Torque Wrenches for low-clearance square-drive work.

What hydraulic power do EAJ tensioners need?

They run on a high-pressure hydraulic pump or a hydraulic power unit sized to the tensioner's working pressure and the number of tools driven at once. Match the pump pressure rating and flow to the tool and keep hoses and couplers within the same pressure rating.

What are the EAJ-QFN quick fastening nuts for?

They speed up the running-down step on the stud before tensioning, which saves time on subsea deployments. See Enerpac EAJ-QFN-Series Quick Fastening Nuts for the matching nuts.

Do you stock seal kits and service parts for EAJ tensioners?

Yes. Enerpac EAJ Seal Kits keep tools serviceable between deployments. Tell us the tool model or the seal size you need and we will match it.

Can you cross-reference an obsolete or unmarked EAJ tensioner?

Yes. We can work from the part number, the bolt schedule, or photos of the tool to match a discontinued EAJ Aquajack tensioner or a competing subsea tensioner by bolt size and tonnage. Send what you have and request a quote.

Enerpac EAJ-Series, Aquajack Subsea Bolt Tensioners

Shop by Enerpac EAJ-Series, Aquajack Subsea Bolt Tensioners Category:

Enerpac EAJ Seal Kits

Enerpac EAJ-QFN-Series, EAJ Tensioner Quick Fastening Nuts

Enerpac EAJ1QFN0750U10, EAJ1 Tensioner Quick Fastening Nut, 3/4 in. – 10 UN Thread Size

Enerpac EAJ1QFNM02025, EAJ1 Tensioner Quick Fastening Nut, M20 x 2,5 Thread Size

Enerpac EAJ1SK, Aquajack AJ1 Seal Kit

Enerpac EAJ2QFN1000U08, EAJ2 Tensioner Quick Fastening Nut, 1 in. x 8 UN Thread Size

Enerpac EAJ2QFNM02425, EAJ2 Tensioner Quick Fastening Nut, M24 x 2,5 Thread Size

Enerpac EAJ2QFNM02730, EAJ2 Tensioner Quick Fastening Nut, M27 x 3,0 Thread Size

Enerpac EAJ2QFNM03035, EAJ2 Tensioner Quick Fastening Nut, M30 x 3,5 Thread Size

Enerpac EAJ2SK, Aquajack AJ2 Seal Kit

Enerpac EAJ3LC, Aquajack Subsea Bolt Tensioner, 1 1/4 in. – 1 3/8 in. Maximum Thread Range

Enerpac EAJ5QFN1750U08, EAJ5 Tensioner Quick Fastening Nut, 1 3/4 in. – 8 UN Thread Size

Enerpac EAJ5QFN1875U08, EAJ5 Tensioner Quick Fastening Nut, 1 7/8 in. – 8 UN Thread Size

Enerpac EAJ5QFN2000U08, EAJ5 Tensioner Quick Fastening Nut, 2 in. – 8 UN Thread Size

Enerpac EAJ5QFNM04545, EAJ5 Tensioner Quick Fastening Nut, M45 x 4,5 Thread Size

Enerpac EAJ5QFNM04850, EAJ5 Tensioner Quick Fastening Nut, M48 x 5,0 Thread Size

Enerpac EAJ5QFNM05250, EAJ5 Tensioner Quick Fastening Nut, M52 x 5,0 Thread Size

Enerpac EAJ5SK, Aquajack AJ5 Seal Kit

Enerpac EAJ6LC, Aquajack Subsea Bolt Tensioner, 2 1/4 in. – 2 1/2 in. Maximum Thread Range

Enerpac EAJ6QFN2250U08, EAJ6 Tensioner Quick Fastening Nut, 2 1/4 in. – 8 UN Thread Size

Enerpac EAJ6QFN2500U08, EAJ6 Tensioner Quick Fastening Nut, 2 1/2 in. – 8 UN Thread Size

Enerpac EAJ6QFNM05655, EAJ6 Tensioner Quick Fastening Nut, M56 x 5,5 Thread Size

Enerpac EAJ6QFNM06055, EAJ6 Tensioner Quick Fastening Nut, M60 x 5,5 Thread Size

Enerpac EAJ6QFNM06460, EAJ6 Tensioner Quick Fastening Nut, M64 x 6,0 Thread Size

Enerpac EAJ7QFN2750U08, EAJ7 Tensioner Quick Fastening Nut, 2 3/4 in. – 8 UN Thread Size

Enerpac EAJ7QFNM06860, EAJ7 Tensioner Quick Fastening Nut, M68 x 6,0 Thread Size

Enerpac EAJ7QFNM07660, EAJ7 Tensioner Quick Fastening Nut, M76 x 6,0 Thread Size

Enerpac EAJ8QFN3500U08, EAJ8 Tensioner Quick Fastening Nut, 3 1/2 in. – 8 UN Thread Size

Enerpac EAJ8QFNM08560, EAJ8 Tensioner Quick Fastening Nut, M85 x 6,0 Thread Size

Enerpac EAJ8SK, Aquajack AJ8 Seal Kit

Enerpac EAJ1QFNM02225, EAJ1 Tensioner Quick Fastening Nut, M22 x 2,5 Thread Size

Enerpac EAJ3QFNM03635, EAJ3 Tensioner Quick Fastening Nut, M36 x 3,5 Thread Size

Enerpac EAJ4QFN1625U08, EAJ4 Tensioner Quick Fastening Nut, 1 5/8 in. – 8 UN Thread Size

Enerpac EAJ2QFN1125U08, EAJ2 Tensioner Quick Fastening Nut, 1 1/8 in. – 8 UN Thread Size

Enerpac EAJ3QFNM03335, EAJ3 Tensioner Quick Fastening Nut, M33 x 3,5 Thread Size

Enerpac EAJ4LC, Aquajack Subsea Bolt Tensioner, 1 1/2 in. – 1 5/8 in. Maximum Thread Range

Enerpac EAJ4SK, Aquajack AJ4 Seal Kit

Enerpac EAJ7QFN3000U08, EAJ7 Tensioner Quick Fastening Nut, 3 in. – 8 UN Thread Size

Enerpac EAJ8LC, Aquajack Subsea Bolt Tensioner, 3 1/4 in. – 3 1/2 in. Maximum Thread Range

Enerpac EAJ1QFN0875U09, EAJ1 Tensioner Quick Fastening Nut, 7/8 in. – 9 UN Thread Size

Enerpac EAJ2LC, Aquajack Subsea Bolt Tensioner, 1 in. – 1 1/8 in. Maximum Thread Range

Enerpac EAJ3QFN1250U08, EAJ3 Tensioner Quick Fastening Nut, 1 1/4 in. – 8 UN Thread Size

Enerpac EAJ3SK, Aquajack AJ3 Seal Kit

Enerpac EAJ4QFNM04245, EAJ4 Tensioner Quick Fastening Nut, M42 x 4,5 Thread Size

Enerpac EAJ5LC, Aquajack Subsea Bolt Tensioner, 1 3/4 in. – 2 in. Maximum Thread Range

Enerpac EAJ7LC, Aquajack Subsea Bolt Tensioner, 2 3/4 in. – 3 in. Maximum Thread Range

Enerpac EAJ7QFNM07260, EAJ7 Tensioner Quick Fastening Nut, M72 x 6,0 Thread Size

Enerpac EAJ8QFN3250U08, EAJ8 Tensioner Quick Fastening Nut, 3 1/4 in. – 8 UN Thread Size

Enerpac EAJ8QFNM08060, EAJ8 Tensioner Quick Fastening Nut, M80 x 6,0 Thread Size

Enerpac EAJ8QFNM09060, EAJ8 Tensioner Quick Fastening Nut, M90 x 6,0 Thread Size

How to Choose an EAJ Aquajack Subsea Bolt Tensioner

Which Bolting Tool Is Right for the Job?

Complete the System

Cross-Referencing an Obsolete EAJ Tensioner

Enerpac EAJ-Series, Aquajack Subsea Bolt Tensioners – Frequently Asked Questions

Quick Buy