Low temperature seals for drilling machines

Arctic drilling are carachertized by working temperatures uo to  -50 ° C. These temperatures creates extremely complex working conditions especially for seals which are made of rubber or plastic.

Challenge

One of our customers, an important manufacturer of winches and windlass, contacted us to replace the commercial oil seals used in standard applications, to allow them to be installed and used on a drilling machine that could work at temperatures down to -50 ° C Moreover the seal should have worked on a system that was not perfectly guided, with a backlash of more than 1.5 mm

Solution

To identify the material that could have best performed in such extreme conditions, ATP technical team run a detailed analysis of the applications, studying their main characteristics:

• Seal diameter: Ø160 mm
• Movement: Rotating; Double Effect
• Quarry: Open
• Media: Hydraulic oil; Mud / stones / earth
• P: 0.5 bar
• V: 10 rpm
• T: -50 ° C
• Backlash: +/- 2 mm

The best material it was easily identified as the ATP’s R&D department had already been studied the same operating conditions for a product usually used in Oil & Gas applications and in the automotive sector. SINTEK H-TPU LT PLUS®, is an elastomeric with excellent wear resistance and characterized by a thermal range between -55 ° C and + 110 ° C.

Lately, the designers, using the technology that analyzes the behavior of the finite elements (F.E.M ANALYSIS), were able to design a sealing system capable of recovering even the large radial backlash (1.5mm) calculated by the customer for this application.

This result was also possible thanks to the aid of a stainless steel spiral spring (element “C” in the diagram) which works as a reinforcing element and a ring in SINTEK UHMW, a plastic material stiffer than SINTEK H-TPU LT PLUS , (element «B» in the diagram) placed inside the seal to obtain an itsown anti-rotation effect.

After testing a couple of solutions directly on the customer’s application (in order to be able to determine the correct interference that would guarantee sealing and radial compensation at the same time), we proceeded with the supply of the entire lot.

Testimony

The customer expressed his satisfaction not only for the resolution of his problem, but also for the extremely fast timing of ATP who carried out the whole project and the subsequent production of the sampling first and the entire batch later, in about 48 hours.