Extending the Lifespan of Your Rotary Unions in Oil & Gas Operations

The oil and gas industry is one of many critical industries that relies on high-quality rotary unions. Rotary unions allow for the transfer of fluids from a rotating component in a pressurized, temperature controlled environment. There are many applications for rotary joints in both onshore and offshore oil and gas operations. These components are often used for fluid transfer in drilling rigs, coiled tubing, hose reels, pipelines, and more.

Oil and gas rotary unions must contend with challenging factors such as abrasive media, high pressure, and harsh environments. Over time, even the highest quality rotary unions will be worn out by these conditions. In this guide, we'll address factors that shorten the lifespan of oil and gas rotary joints and ways that you can extend the lifespan of these fluid transfer solutions.

Main Factors That Affect Rotary Union Lifespan

• Media Type – Rotary unions used for oil and gas applications will often have to transfer fluid that is abrasive and possibly corrosive. While clean hydraulic oil causes minimal wear and tear, that's not the case with other media such as sandy or saline water and dry gases. Regular transfer of these abrasive materials through a rotary union can cause the materials used in seals and housings to degrade quickly, shortening the component's lifespan.
  
  If you want to get the longest lifespan out of your rotary joints, be sure to select units built from the right materials for oil and gas applications. Some types of seals are more vulnerable to corrosion than others; make sure your rotary joints have seals that can withstand the media they'll be transferring in the long term. It's equally crucial to choose fluid transfer solutions with housings made of stainless steel or another corrosion-resistant material.
• Pressure – While rotary unions are built to withstand high levels of pressure, operating under higher pressure increases seal face loading and friction. This accelerates wear, generates more heat, and can cause premature leakage in oil and gas rotary joints. Sudden fluctuations in pressure are particularly damaging; they can cause seal face separation and rapid degradation.
  
  Operating close to a rotary joint’s rated pressure limit significantly shortens its lifespan. If you want your rotary unions to function for as long as possible, be sure to choose products with safety margins well above expected pressure levels.
• Temperature – The excess heat that rotary joints may encounter in oil and gas operations can shorten their lifespans. High temperatures damage seals and bearings, soften elastomers, reduce lubricity of fluids, and cause thermal expansion of components. Low temperatures can prove problematic as well since they can make seals brittle and cause leakage or cracking. Another problem encountered in oil and gas operations is thermal cycling, which stresses seals and housings, reducing the lifespans of rotary joints.
  
  For longer rotary union lifespans, it's necessary to provide proper cooling and insulation. If fluid temperatures are often very high, rely on rotary joints designed with cooling jackets or thermal-resistant seals.
• Rotational Speed – At high rotational speeds, rotary unions experienced increased frictional heat at the seal faces and centrifugal forces on the media under transfer. At extremely high RPM, lubrication films may break down, causing dry running conditions. Dry running results in rapid seal wear, which may significantly shorten the lifespan of your oil and gas rotary joints.
  
  Because high RPM operations will shorten the lifespan of rotary joints, it is best to avoid pushing rotational speed limits as much as possible. Make sure your rotary unions have the appropriate RPM ratings to minimize frictional heat wear.
• Duty Cycle – When rotary unions have a continuous duty cycle - such as 24/7 oil drilling operations - they will be worn down continuously and may experience shorter operational lifespans. However, start-stop cycling comes with its own stresses. During start-stop cycles, rotary unions may suffer degradation as a result of shock loading and pressure surges.
  
  Oil and gas rotary unions used in continuous duty cycles may experience a longer lifespan, provided they aren't regularly being pushed to their limits. Frequent start-stop cycling will wear down rotary joints faster, but allowing cooldown and recovery time between cycles can minimize the harmful impact on your fluid transfer solutions.

Additional Tips to Maximize Rotary Union Lifespan

• Use precision alignment tools during rotary union installation; misalignment between the union and the rotating equipment is one of the top causes of premature seal wear.
• Use proper mounting support and flexible connections so that your rotary joints aren't carrying excessively heavy loads.
• Implement proper filtration and flush systems to protect your rotary unions from abrasive particles found in drilling fluids and hydraulic oil.
• Keep up with routine maintenance for your oil and gas rotary unions. Lubricate them regularly, and perform inspections for leaks and unusual vibrations.

Top-Tier Rotary Unions for Oil & Gas Operations

DSTI is a manufacturer of high-performance rotary unions that are ideally suited for oil and gas operations. Contact us today if you'd like to learn more about our inventory of single passage and multi-passage rotary unions.