Small Rod Wipers? (Or other reliable gasket material?)

In summary, Dan is looking for a setup that would allow a 1/8" diameter steel rod to slide slowly with cold oil on one side and air pressure on the other. He is looking for a seal that can withstand the pressure and found that rod wipers are not suitable for this purpose. Instead, he was recommended to use O-rings or other types of seals such as urethane cups or Teflon U-cups. He was also given a specific part number from McMaster Carr and advised to consult the Parker O-ring Handbook for more information.
  • #1
BasketDaN
96
0
I'm looking for a 1/8" diameter rod wiper, or anything else that could be reliably used to allow a 1/8" diameter steel rod to slide very slowly past it while maintaining cold oil (at about 0 celsius) on one side at several hundred psi, and standard pressure air on the other side.

Anybody know of somewhere I could find such a setup? I can't seem to find anything that small

Thanks
Dan
 
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  • #2
Hi Basket. Rod wipers are typically not meant for sealing purposes. They're made to wipe dirt and other solid particulates off a rod prior to the rod going through a seal so as not to damage the seal. What you want is a seal of some kind.

Rod seals like this are typically O-rings, urethane cups, quad seals, Teflon U-cups or similar types of seals. They can also be purchased with Teflon wear bands if wear rate is a concern. Since you have oil on the pressurized side, and pressure is relatively low, you probably don't have to worry too much about wear of the seal.

If you need a specific recommendation, the first thing that comes to mind is to look on McMaster Carr. They don't have the urethane cups that small (I'm sure other places do) but they have various O-rings. I'd suggest part number 90025K513.
http://www.mcmaster.com/#90025k513/=2qxpr7
 
  • #3
Thank you very much! Good thing I didn't waste more time looking around for rod wipers.

O-rings are pretty easy to find; will they be fine for under 1,000 psi?
 
  • #4
The pressure that O-rings can be used at is primarily dependant on the material, how soft/hard it is, and any extrusion gap between the moving parts. O-rings at high pressure can be thought of as being a bit like a fluid in that they conform to whatever pocket they are contained in and will try to extrude into small clearances. Attached is a typical graph of extrusion gap versus pressure and hardness.

Also, the bible for O-rings is the Parker O-ring Handbook. Lots of great information in there, but it's a fairly large download.
http://www.parker.com/literature/ORD 5700 Parker_O-Ring_Handbook.pdf
 

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1. What are small rod wipers and what are they used for?

Small rod wipers are small gaskets made from a durable and flexible material that are used to prevent dirt, debris, and other contaminants from entering and damaging hydraulic or pneumatic cylinder rods. They create a tight seal between the rod and the cylinder bore, extending the life of the cylinder and reducing maintenance costs.

2. What are some common materials used for small rod wipers?

Some of the most commonly used materials for small rod wipers include rubber, polyurethane, and Teflon. Each material has its own unique properties and benefits, so the choice will depend on the specific application and requirements.

3. How do I know which small rod wiper material is right for my application?

The best way to determine the right material for your small rod wipers is to consult with a manufacturer or supplier who specializes in gasket materials. They will be able to evaluate your specific needs and recommend the most suitable material for your application.

4. Can small rod wipers be customized to fit specific cylinder sizes?

Yes, small rod wipers can be customized to fit specific cylinder sizes. Most manufacturers offer a range of standard sizes, but they can also create custom sizes and shapes to meet the specific requirements of your cylinders.

5. How often should small rod wipers be replaced?

The lifespan of small rod wipers will vary depending on the material, operating conditions, and frequency of use. In general, they should be replaced when they show signs of wear or damage, such as cracks, tears, or loss of elasticity. It's also recommended to replace them during routine maintenance to ensure optimal performance and prevent potential downtime or damage to the cylinder.

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