I am very much in need of your expertise. I have been contacted by a company to evaluate a fitting (connects hose to loading station to receive fluids) as employees expressed concerns that this fitting causes increased shoulder discomfort. I have been in contact with the manufacturer regarding push/pull specs and have received the following information. Newer style handles require 0 torque for push and 5 ft/lb for torque for rotation which is a 1/4 turn (90 degrees). The newer swivel handle doesn’t even require a full 1/4 turn. The older styles require 32 ft/lb torque to push onto male end and 18 ft/lb torque for rotation. I am not convinced that it is specifically the fitting that is causing the issue as it takes 12 seconds to complete the connection and it is only done 16 times in an 12 hour shift. Has anyone encountered this before or had a similar situation? Any suggestions would be greatly appreciated!!!
Where is the connection located? Is it overhead? Is it located underneath something? Where I’m at, we use pneumatic connectors and most of the time, the connections are located overhead. This does make it a bit difficult, even if it’s done infrequently.Jeff de los Santos
Hello Jeff The connections vary. Some are at waist, above chest and knee height. In some stations there is a water basin extended underneath the connection which causes the worker to reach out from the body. I am not familiar with pneumatic connectors. Does this make it easier on the body? Thanks Sandra
These are basically quick-disconnect type connectors. You need to push them in to either connect or disconnect.Jeff de los Santos
The HSE has done a cost benefit anaysis of potentially a similar probem in one of their studies that may be of benefit. You may also want to look at the other task the employees are performing as this may be contributing to the problem. Possible reductions in hose length depending upon how long they are. Maybe a system that presents the couplings to each other with less hose length and consequently less hose and distance to carry. Maybe locating the hose at about waist height. The HSE document showed a significant cost advantage by going through this process. Are ther other couplings that require less force that would do the job?
You say the connection takes 12 seconds to make. That is not a quick-connect connection, quick-connect take less than two seconds.
The pipes contain fluid. How long is the pipe between the connector and its first support, and what diameter is the pipe? If the operator has to support a heavy flexible pipe and pull it to get the connector in the correct position, there is a good chance of injury.
Please supply more details of the operation.
This specfic attachement is not a quick connect. The company decided to try a different version due to the lack of safety in the quick connect that did not prevent the liquid splash back on the worker if they removed the connection before ensuring the line was empty. This new style of adapter requires placement and torque to the right to connect with a safetly handle that must be engaged. The average size of the hose is approximately 15 cm (6 inches) in diameter. The weight of hose + adapter and fitting could be 10 kg for approximately 5 m. Most docking stations can be accessed within 5 m, but there are a few that require up to 10 m. There is no support in place for the hose and my major concern iat the time was the different heights and locations of the docking stations themselves as this is variable. When there is an optimal station within easy distance and proper height even the workers state it is easy. I do like the idea of a support though. Do you have any further information regarding this?
That is no garden hose is it!
If it is full of water, the water would weigh around 12 lb/ft. (I still estimate in imperial units.) Just the water in 5 m of pipe would weigh close to 200 lb. So the hose is empty while the connection is being made.
I have never used such a large hose, but it alone must be quite heavy. 6 inch standard schedule 40 steel pipe weighs about 19 lb per foot, so a 6 inch hose probably weighs at least 5 lb per foot. End fitting are solid metal so must weight around 5 lb. Total around 100 lb. Your estimate of 10 kg for 5 m of hose and the end fitting could be low.
Instead of the operator providing vertical support, maybe you could thread your hose through a foot long piece of 8 inch pipe that has a loop welded to its centre. Then support the loop using a chain falls. The 8 inch pipe would be a saddle for the 6 inch hose to sit on. The higher you can set the anchor point for the chain falls the better, as the force to push the hose around will be lower. The chain falls would enable the height to be controlled very easily by hand. You may need more than one support, especially as the weight of the hose goes up dramatically when it is filled and you don’t want the hose to develop any kinks. When the pressure in the pipe increases, the hose will try to straighten and this could cause more interesting situations.
Hello Colin Thanks for the quick response. I think a support system of some sort might be very beneficial for the connecting part, but would that increase the drag force for the worker if they have to pull through something? Could I actually decrease the work load on the worker particularly the upper body with a support system or would I transfer stress to a different area? What are your thoughts? It sounds like you have seen or used some sort of support system. Does the worker have to carry this or move it? Can it be stored along side the truck somehow or would it need to be in place at each loading station? Looking for any ideas I can present at this point in time. Thanks Again Sandra
I see that you now mention a truck. Maybe this is either a fire truck or a grease pump truck. Have you spoken to the supplier of the truck? They may well have an optional extra support or something that was not chosen when your truck was built, or your truck may have been an early model.
If that fails, you will have to make something yourself. The “chain falls” that I mentioned is a type of manual hoist that uses a chain. Sometimes it’s called a chain hoist. I have a catalog that shows a chain hoist that can lift one ton for ten feet; it weighs 28 lb and costs about $250. Have a look at some on Google Images. I envisioned it anchored to an eye bolt or similar maybe 20 feet above the ground. Even 10 or 12 feet from the ground may be enough. The saddle pipe would support the hose near the hose end. The hose would not be slid through the saddle pipe. Instead the chain falls would act like an adjustable length rope and the end of the hose could be easily swung up to five feet or so from directly under the eye bolt.
The worker would raise and lower the hose by pulling downwards on one or other of the loops of the chain falls, where an easy 20 lb pull may be enough to raise an 800 lb load. Then he would swing the hose over to the fitting by pushing it horizontally.
If you wanted to attach the anchor point to a truck, you would have install a strong post and ensure that your attachment will not weaken the truck frame. You may also come up against height limitations. This work should be done by a company that outfits trucks and knows enough to do it without invalidating your truck warranty and insurance. Another alternative may be to attach a pneumatic or hydraulic powered support system to the underside of the truck.
If all the connection points were at the same level (30 inches above grade could be a good height for handling the hose) and in a line at the side of the truck, you would not need vertical adjustment for your hose end. Maybe you would need a support bar for the hose a couple of feet away from the connection points to avoid kinks. The support bar could be on a hinged frame that hangs against the truck side during transit. This arrangement would just require adding a few bits of pipe and the support bar.
(Part of my background is with the design of heavy electrical equipment, cabling, and controls, where constructability, operability, maintainability, safety, and human factors have to be taken into account. The equipment also has to fit in amongst the building structural elements, piping, mechanical equipment, etc..)
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