Know The Significance Of Hydraulic Bolt Tensioner

In Europe, hydraulic bolt tensioner is more often employed than in the United States. Although hydraulic tensioning is most often utilized with bolts 2 inches in diameter or more, it may be used with studs as tiny as 34 inches. 

The oil and gas business makes less use of tensioners than the subsea (both topside and undersea) sector, the wind turbine sector, and the power production sector. Yet, tensioning tools find useful use on fasteners in crucial bolt-on connections in the oil & gas sector, including heat exchangers and huge pressure vessels. 

Compressing gaskets evenly and precisely is easier with tensioner protection of 50% or more compared to only using one or even four torque wrenches.  

Hydraulic bolt tensioners often allow for more stud bolt reuse by removing the need to worry about galling or the effects of friction on the fastener. It may be the case in the lab. Still, it’s important to remember that operational circumstances like humidity and pressure will continue to impact the fasteners as time passes in the outdoors. 

Field Application of Bolt Tensioners:

The necessity for more room is a drawback of tensioners. Although a tensioner isn’t usually a problem on standard pipe flanges, it may be on valves and other specialized flanges on heat exchangers. 

In addition, most fastener tensioners have an allowed stud preload of 50,000-60,000 psi. Over 60,000 psi of tensioning pressure often requires a specialized tensioner. 

Extra stud length is required for tensioning as well. The stud must protrude from the nut by at least one diameter for the puller bar to securely grasp it under pressure from the load cell. Thus, to get the correct size, add further diameter to the standard stud length often used for torquing. 

Never pair a tensioner plus a washer. A tensioner’s footprint might rest on a washer, bending it out of shape so that the tensioner can lock in place as per the bolt tensioner manufacturer.

Tensioners also struggle to function properly in hotter environments. A definition, please. While torque wrenches are OK for the normal re-torquing required at starting, the tensioners’ seals would blow and not hold the pressure. So, when it comes to tensioning, you can easily build the flange at room temperature, yet you can’t execute what certain individuals term a “hot tension run” after starting.

Hydraulic Tensioning: How Does It Function?

The fundamentals of a hydraulic tensioner, from the base up, are:

Nut: The bridge rests around the nut, and this rests on the flange. The nut has a hole for the bolt to pass through; additionally, the stud has to poke out of it by at least a single diameter. 

Load cell: It is located atop the nut and houses the hydraulic piston. The tensioner pump’s oil enters the load cell via a nipple at a predetermined hydraulic pressure. 

Puller bar: The piston threads onto this, and it rests on the stud. The amount of pressure you can put on the bolt depends on the load cell size and the hydraulic pressure in the pump itself.

Security in Hydraulic Tensioning

Hydraulic tensioning security is of the utmost importance. The principal source of danger is the high-pressure hydraulic fluid that flows from one set of tensioners to another through a load cell. Be very careful while handling high-pressure fluids; they may cause serious damage if not handled correctly. Please repair any hoses or fittings that are worn or broken. 

Additionally, when the tensioner bursts off during usage due to inadequate thread participation, stripping, or whatever else, it becomes a bullet, and your assemblers aren’t inclined to be gazing down at it. Be sure you’re on the tensioners’ side instead of staring down at the pulley at all times.