A customer received some feedback regarding an issue with a set of leaking flat face couplings and heavy brinelling* evident on the male part of the coupling.
Holmbury prides itself on the quality of all our products, so it was a priority for us to ensure these couplings made their way back to undergo rigorous inspection at our state-of-the-art test facility in Tonbridge, Kent. Once the goods arrived at our site, we carried out our standard inspection checks and tests. Supporting report documentation, complete with images, to convey our findings was prepared for the customer.
Our investigation had revealed the leakage was due to the seals being extruded alongside the very clear brinelling. Further discussions with our customer followed and we learned the couplings had been subjected to a combination of extreme pulsing and hose vibration which on this occasion took the application out of the performance zone of the HQ flat face series. It was clear to our technical team that our customer required a different coupling solution to resolve this issue. Holmbury advised that our HFT series could be a good solution.
HFT series screw to connect couplings incorporate all the benefits from our HQ range, whilst simultaneously strengthening the connection. Eliminating brinelling. Connection and disconnection can take place at high residual pressure in both the female and the male coupling, thus make the HFT series an ideal solution for high pressure pulses.
Our customer purchased several sets of the HFT series couplings and throughout the last 6 months we’ve had no recurrence or issues.
Holmbury continues to work closely with our customers when problems arise. Modern machines which, on the surface do the same job as they always have, have higher performance characteristics than previous models meaning higher performing couplings are sometimes required.
Rest assured that our team will always be ready to offer technical support when you need it and a solution to keep your equipment up and running.
For more information, please visit the rest of our website or call our sales office on 01732 378912.
* What is Brinelling? Brinelling is a type of mechanical damage that occurs on the surface of a metal object when it is subjected to extreme pulsation – in the case of a quick release coupling the ball bearings cause indentations to the coupling itself generally due to the above and excessive side loading of a heavy, unsupported hose assembly.
Holmbury HQ series flat faced couplings are used on many, many applications, and attachments. Here are just a few. Thanks to FH & J Alviti for their participation! Visit the following link to see them in action…
https://www.linkedin.com/feed/update/urn:li:activity:6951096166356799488
Products featured were:
HCP Series– Male flat face connect under pressure coupling
HFT Series– Male/female screw connect, flat face connect under pressure coupling
HDB Series– Decompression block coupling
MP Series– Multiplate coupling
For more information on any of these products get in touch with our sales team.
The Holmbury Roflex Series Couplings should provide years of reliable service in the most demanding applications when used properly.
Over time though, the internal parts may wear due to dirty oil passing through the coupling or other factors.
There’s no need to worry though. Holmbury offers repair kits for each sized coupling and it allows you to completely rebuild the internal parts of the couplings and the process is very simple.
Utilizing the repair toolkit consisting of a T-wrench, calibration disk and staking tool, which are all sized for the particular coupling size being repaired, along with the appropriate repair kit consisting of a poppet, spring and retainer for each coupling half as well as the seals for the probe half, you have all the components necessary to fully rebuild the couplings.
It is imperative that you only rebuild one coupling half at a time as you need to completely assemble mating coupling to ensure proper spacing of the parts.
I’ve already removed the internal components from the cut-away model as you can see. It is recommended that you thoroughly flush the coupling with mineral spirits or a similar type solvent to remove any loose debris, being careful to allow adequate ventilation and observe proper safety precautions.
Insert the calibration disk into the half you are repairing and screw the probe and sleeve together until the disk is fixed. Insert the new poppet, spring, and threaded collet into the half you are repairing and tighten with a T-wrench until the spring is fully compressed.
Then turn back counterclockwise one-eighth of a turn. At this point, you would set the still assembled coupling upright on a flat surface, insert the staking tool through the port of the newly reassembled half and into the slots of the collet, striking the tool firmly with a hammer to sufficiently distort the thread of the collet, so it will not loosen when subjected to the severe hydraulic pulsations these couplings are designed to withstand.
Unscrew the coupling halves and remove the calibration disk. If repairing the probe half, insert the O-ring first and then the back-up ring into the groove.
Now you can repair the other half using the same procedure and when completed, you will have a set of couplings that should give you many more years of productive service.
If you were in the market for a quick disconnect coupling that will stand extremely severe hydraulic pulsations and applications such as shears, breakers, rock crushers and hammers, look no further than the Holmbury Roflex Series screw-to-connect couplings.
The simple yet robust design includes three key elements that allow these couplings to hold up to the most demanding applications as demonstrated by this cut-away model.
First you will notice the poppet is fully guided in the chamber, preventing it from shifting off center like other designs.
Next, when connected, the spring is fully compressed and the poppet is held rigid, preventing rapid pulsations from fatiguing the poppet, spring or the coupling itself.
Finally, the spring and poppet in each half are retained by a very rugged collet that will not back out or disintegrate under severe forces. The Roflex Series is available in port sizes ranging from three-eighths to two-inch BSPP and can accommodate flows up to 130 GPM.
The engineered seals and poppet design enable the operator to connect and disconnect with trap static pressure in one or both lines.
Rated working pressures range from 7250 PSI for the three-eighth size down to 3625 PSI for the two-inch size. It is important that you use the proper sized coupling for your application based on the maximum flow rate specified in the Holmbury catalog to avoid premature seal wear.
When sized correctly, the Roflex coupling should provide years of reliable service and eliminate costly downtime. Give Roflex a try and see for yourself.