Help in finding a threaded polyethylene bush

[don4000]

I would appreciate a little help.
Im in the process of designing a small hand operated pump, similar to a stirrup pump. I need a polyethylene bush which the vertical rod will pass through. The hole for the rod to pass though will be about 10mm. The bush will screw into a BSP pipe, size to be confirmed, but the bigger the better. I can modify my design to fit a suitable bush.
Can anyone know of an off the shelf male threaded bush, with a 10mm hole in it?
I like in the UK, if that helps.

Thank you for your time

 

[Artisi]

Local machine shop, get them to make exactly what you want.

 

[Compositepro]

You will rarely see a design like you describe because there are much better ones that are commonly used. Urethane is aplastic material which means that it deforms easily. Such "bushings" are also called "packing". The plastic bushing is smooth on the I.D. and the O.D. It is held in place and compressed by a threaded metal bushing like you describe. The metal bushing is tightened to compress the plastic bushing and adjust the clearance with the shaft. This allows for wear compensation and prevents the plastic bushing from deforming under pressure from contact with the shaft.

 

[don4000]

Thank you for your input. Let me explain.
This stirrup type pump will be used and possibley assembled in rural Africa where skill levels are extremely low.
I need something ready simple that can be repaired locally. Here is where I am.
I have a 2 inch BSP pipe with an internal thread. I need something that fits into this that has a hole in it (ie a “bush”) for a 10mm stainless steel rod that is one meter in length.
I need off the shelf parts that can be shipped and assembled on site.
I understand that the “bush”of the pump, with the up down motion will wear. Therefore I need an off the shelf part that can be replaced with a wrench.
Local conditions may be sandy, so wear is a factor.

Thank you for your interest and help

 

[Artisi]

Do you really think that an "off-the-shelf" item such as this will be available in rural Africa - think again.

Have the bush made to suit want you want to suit the pump and supply a few spares with each unit.

 

[don4000]

The plan was to use off the shelf components to reduce the cost.
Im well aware that rural Africa will not be in a position to provide “off the shelf” items. Part of the project, is at a later date was to move assembly to rural Africa. It’s for this reason that the local machine shop solution is not really viable.

Again that you for your help

 

[Artisi]

I think you need to look at reality and accept that it is more than likely that you cannot source this in the UK "off the shelf" and therefore impossible in rural Africa.

I have been involved in this type project and know first hand that some items have to be supplied ex UK/ Australia / USA etc.

Or redesign to suit what is available locally.

 

[ScottyUK]

Any possibility of making the 'bush' out of hardwood, slightly oversized so that the thread of the pipe cuts into it? That would be field-replaceable and if I picture this component correctly it is a fixed guide bush through which the pump rod slides, and not part of the plunger assembly.


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If we learn from our mistakes I'm getting a great education!

 

[don4000]

Scotty

Thanks for the suggestion, but hardword wont work, the fixed guide bush is externally threaded into a 3in BSP female pipe.There is no lathe locally to turn the wood.
The fixed guide bush has a 10mm hole to allow the rod to slide up and down.
Remember Im not trying to made the components,locally. Just trying to find cheap components that can bought in the UK and shipped to Africa in kit form and assembled in the bush.

Thank you for your interest