Due to its size and complexity, a petrochemical refinery offers many potential safety hazards, one of which is rubber steam hose that blends into the scenery and presents many hidden-in-plain-sight risks. If a steam hose assembly fails, a potentially lethal hazard may be unleashed unexpectedly, quickly, and with overwhelming force upon defenseless workers.
Here is a simple, successful approach to converting a petrochemical refinery over to using crimped steam hose assemblies for a safer work environment.
The petrochemical refinery management team is usually not composed of “hose people.” So you (or they) may not be aware that steam service is one of the most rigorous applications for rubber hose, as heat is the arch-enemy of most synthetic rubber compounds. Large volumes of refinery steam are conveyed in fixed metal piping, with flexible hoses attached to allow the steam to be more easily deployed. The steam provides wet heat to lubricate and increase flow in applications such as tank and vessel cleaning, and to keep process equipment running smoothly and efficiently. When in service, the heat and moisture of the steam expand the rubber, and after use, the hose dries out and contracts. Each cycle jeopardizes the security of fittings installed with bolt-on clamps.
Traditionally, rubber steam hose assemblies have been fabricated using re-attachable fittings installed using external bolt-on clamps.
More recently, rubber steam hose assemblies have been fabricated using hydraulic-style permanent crimp fittings installed using a high-pressure hydraulic crimper.
Hose assemblies using traditional re-attachable fittings
the components (hose, fittings, clamps) are usually produced by different manufacturers.
are not designed or tested as a bona fide system.
are attached by clamps that do not have contact with the entire circumference of the hose.
are susceptible to leakage at the hose/fitting interface.
because the hose is constantly expanding and contracting, the fittings/clamps need frequent maintenance.
require a visual inspection, tightening of the clamps using proper torque settings, etc.
clamps are heavy and bulky and present a tripping/bumping hazard.
over time, the clamps can no longer be tightened as much as needed, undermining the efficiency and safety of the hose assembly and requiring premature rework or replacement.
Hose assemblies using permanent crimped-on fittings
Perform a plant assessment or survey to determine
which type of steam hose assembly is deployed (there might be a mixture)?
is there a hose assembly visual tagging system? Or better yet, a hose assembly computer database such as the Parker Tracking System (PTS)?
if routine maintenance is being performed?
are clamp bolts being inspected/tightened? If so, are they being tightened according to the proper torque/spec?
what is the time/cost of maintenance?
what is the cost of steam loss/system inefficiency?
what is our steam hose safety record?
Finally, consider that Parker Hannifin pioneered steam hose crimped assembly technology and that we have validated steam hose assemblies with the same engineered care and precision used to qualify high-pressure hydraulic hose assemblies.
Article contributed by Dennis Daniel, technical services manager for Hose Products Division, Parker Hannifin.