One of the biggest issue of owning a scroll pump is tip seals wear out fairly quickly and can be expensive to replace. Many scroll pumps are essentially totaled if kits can't be found readily. This section is about evaluating the merits of making DIY tip seals
Understand wear profile of different materials. Ex: for hobby use a lower grade material may be good enough for low duty cycle
How to know when tip seal is running low without opening / hearing grinding? What it be helpful to install hour counter?
- We have made our own tip seals before
- Stopped since they seemed to last a little under half as long as the proper ones
- Resilient Polyurethane Foam Sheet
- with Adhesive-Back, Medium, 12" x 12" x 1/16"
- Slippery UHMW Polyethylene Film
- Adhesive-Back, 12" x 12" x 3/64"
- then it's just held in the frame pictured above and waterjet
- the little bit we have left says UH-9, PORON
- I mean we also run 24/7
- so tip seal replacements after about a year of runtime instead of 2-3
- also the DIY ones definitely produced more "dust"
- Tip Seal PTFE Filled Bronzed Wear Strips Special Designed for Scroll Compressor
- PTFE + Bronze
- Also used in hydraulic cylinders
- "it seems like you can get them in a mix of bronze, carbon, and MoS2"
Anything quick to try?
- Roughly the right size but too high friction
Sample commercial pricing. Keep distributors anonymous unless they explicitly list pricing
|Busch||FO 0018 C OHO||Tip seal||$545.00
|Busch||FO 0018 C OHO||Full||$3928.00
|How much does a pump cost..|
|Edwards||nXDS6i nXDS10i nXDS15i & nXDS20i||Tip seal
Compatibility between these? Could we match one of the less expensive kits to one of the more expensive pump rebuilds?
Some suggested that these can only be injection molded
Suspect these can be (waterjet?) cut from sheets or simply applied as strips
Laser cutting probably isn't precise enough and would produce nasty fluorinated fumes
Milling might work (with enough support) but will waste a lot of expensive material
Busch black gasket material analysis
- Suspected to be bronze filled PTFE
- FTIR has confirmed PTFE is primary organic
- EDS analysis pending
Busch gasket dimensions
- Maybe 2.5 mm => 0.0098" square
- Channel: maybe 0.075"
- Gasket (worn): around 0.080"
- Channel: maybe 0.095" wide
- Gasket: maybe 0.096" wide
- Scroll area: around 7"
- Length needed: around 276" (23')
- Gasket length: around 69"
- Gaskets: 4
McMaster-Carr has bronze filled PTFE sheets
Scrolls [walls] are anodized aluminum
[gasket] likely Class 3 PTFE filled
that 1045 is even more likely
Rulon J can be made in thin film form
Looking at some rebuild kits
- official kit has green viton orings not brown [for general gaskets]
Other option could be use something like PTFE bronze that could wear off easier but it's 10X cheaper so you would endup changing the seal more frequently but without custom built orders
- Suspected Rulon J or XL
- XL - is polymers only
- J has something else
- Rulon 142 has bronze
- New edwards pumps dont use black tip seals
- Red stuff is Rulon LR
- Identifying Rulon variants
- About Rulon 142