Tungsten Carbide/Molykote/Xylan Coating for the upstream equipment (Oil and Gas) 2

[JHWC]

Hi All,

In my current company, we often recommend tungsten carbide, molykote and xylan coatings for upstream equipment.

The reason for coating? Probably to increase the lifespan and the prevention of any corrosion.

Often, I hear the word, "cycle" being used.

I am curious. How do one define "cycle"? For example, xylan can last 10 cycles. What are 10 cycles equivalent to?

Thanks for the kind help in advance.

Jeffrey

 

[CoryPad]

Assembly + use + disassembly = 1 cycle.

 

[JHWC]

Thanks CoryPad.

Just 1 question, could it co-relate with number of hours?

Thanks,
Jeffrey

 

[moltenmetal]

Zylan and molykote are fastener coatings. I've never seen a tungsten carbide coating on a fastener. Sometimes such coatings are used on seals or other parts too, but their usefulness and resistance will depend on what they're being used to coat! In an application such as fasteners, their greatest risk of damage is while they are being tightened or untightened, hence the "cycle life".

 

[CoryPad]

Jeffrey,

There should be a basic correlation between number of hours and number of cycles. Contact Whitford to discuss expected lifetime of Xylan in your environment.

Cory

 

[tbuelna]

"cycle" can mean different things depending on how it is used. There are thermal cycles, load cycles, operating cycles, installation/removal cycles, etc. For example, the length of time involved in a single thermal cycle can vary significantly. For example, the crown surface of a recip engine piston can experience several thousand thermal cycles per minute. And the length of time involved in a single load cycle applied to a structure might last just a few milliseconds or several days.

As others noted, coatings like MoS2 DFL or Xylan applied to fastener threads are probably rated based on installation/removal cycles. This data is typically an average result from testing a number of similar specimens under controlled conditions. Coatings applied to surfaces for corrosion protection can improve fatigue characteristics of a metal component by preventing formation of surface defects from corrosion. Presence of surface defects will reduce the statistical fatigue life of a metal component.

 

[JHWC]

Hi CoryPad, moltenmetal, tbuelna,

Thank you for the explanations. I will take note of that.

Cheers,
Jeffrey