Steam, hydraulic oil, high velocity gases, and dielectric fluids can generate static charge when passing through a hose core. Brush up on hose selection factors that affect plant safety and efficiency.
Steam and fuels can generate static charge when passing through a hose core, and these applications usually require a hose core that can effectively dissipate static buildup materials. Otherwise build up of electrostatic charge "can cause a tiny hole in the hose to develop, resulting in a hard to detect system fluid leak and providing a path for any pent-up static electricity to jump to the closest conductive material," Swagelok explains in a new video (below) which includes photos of damage that can result:
Above: Examples of damage from electrostatic discharge.
System media is a key component in proper hose selection. Identify the system media and the environment to which the hose assembly will be exposed. This will help determine the materials of construction best suited to the application demands and whether the hose requires a static dissipative core.
Swagelok emphasizes that conductive hose is not necessarily static dissipative, and vice versa. This video explains the difference:
Static dissipation means safely discharging static buildup, while conductivity means transmitting an electric charge. Consider our Hose Advisory service to get a hand with minimizing hose problems.
"In a static dissipative hose, it is the hose's core material that can dissipate small static charges to an area outside the hose," viewers learn. "Typically this is done by allowing the small charges to flow to the braid material and then to an end connection." An illustration:
Let's look at an example. PTFE is not a good conductor of electricity. The flow of electricity can be impeded when fluids that are good conductors, like steam or fuels, come in contact with each other. Therefore static electricity can be generated by fluid passing through the hose.
Although PTFE is non-conductive, it can be modified with sufficient conductivity to ground the static electric charge, eliminating the risk of catastrophic failure from charged particles arcing through the PTFE core. Indeed, static dissipative core tube versions are available for Swagelok PTFE hose. These conductive versions incorporate an extruded core tube of PTFE with an inner surface of carbon, often referred to as smooth-bore, carbon black-filled PTFE core. Any electrostatic charges are conducted to the end connection which are subsequently grounded.
Technicians we work with have to check, maintain, repair, and replace hundreds —or maybe thousands—of feet of hose at their facilities. With the pressure on to minimize man hours, it may seem like a safe bet to install a new version of a worn hose when replacement is necessary. But matching an older hose's features can be risky.
Analytical instrumentation equipment, for example, may have changed since the original hose was selected. Some older analytical equipment was built in a way that required a large sample of chemical or mixture to meet the requirements for a good reading. Today's more sensitive equipment can get the job done with smaller samples, but is also more susceptible to an unwanted electrical change.
It is critically important to use hose with the right static dissipative and/or conductivity properties. We offer dielectric fittings and adapters too. These types of components can additionally isolate monitoring instruments from the effects of electrical current.
This service is aimed at applying Swagelok expertise to minimize your hose maintenance, repair, and replacement costs. Learn more here:
This collection delivers technical briefings, a quicklook sheet, relevant literature, articles by our local team, and more — all in one step. Free download here:
Understanding the fundamentals of hose and flexible tubing helps to extend hose production cycles, promote safety, and lower total cost of ownership. View 2023 class dates and get a free PDF with course info here:
We build hose in our Fremont shop — sometimes with same-day turnaround. We can combine any of 22 types of hose with any of 89 end connections, in almost any length, in small or large quantities. Includes testing. Learn more:
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