spray & fuse question

[Brent]

We are currently quoting to manafacture some pump sleeves and are having troubles on the best procedure to make them. Usually when we make a 316SS sleeve for spray and fuse we leave the ID quite under size so the material doesnt warp during the wetting in phase. The dilema is the most affordable material we can get for the current quote will be about .350" wall thickness during wet in. The sleeve will be 5.625 OD and 13.5" long I am wondering if anyone has had much experience with spray&fuse on sleeves this size?? Most of our previous experince is with smaller diameters and shorter sleeves.
Which brings me too my 2nd question this job is going to be sprayed with a colmonoy 88 and will see low ph solutions(either bleach or brown stock) I am wondering if maybe a hvof applied coating would work in this instance???? in resistance to the enviroment and ease of application.
Any help is always appreciated
Brent

[KevGarty]

There are a few HVOF powders which can be fused e.g Metco D2001

If you can find a powder which would suit the application you would certainly be hell of a lot quicker than using oxy/accetelyne etc (I take it thats what your using at the moment ?)

Ive seen guys fusing very long shafts around the same diameter but it was down to availability of materials. If you have the option of time on you hands I would look into a hvof powder that you may not have to wet in? Speak with wallcollmonoy see if they can come up with anything. David Allnatt is a really helpfull guy.

Dont know if thats much help mate

[rbateriwala]

1) Using colmonoy 88 with HVOF is the easiest procedure. We advise rotation at 20 rpm, preheat 90 deg C before spraying with HVOF based on our experience.
2) For the sleeve size you specified for a diameter of 140mm approx, you can use the following procedure:
Mount the sleeve on a rotator (lathe), rpm around 20. heat the job to a temperature of 150 deg C and spray around 150 micron thick layer. stop rotation of lathe and fuse the layer. Built to desired thickness and fuse stationary. Commence rotation at higher speed to reduce deformation possibilities.
As it is colmonoy 88 fuses easily.
3) Properties(wear resistance) achieved after fusion are much better.
I all cases usual surface preparation should be carried out.
regards
Ragesh Bateriwala

We are currently quoting to manafacture some pump sleeves and are having troubles on the best procedure to make them. Usually when we make a 316SS sleeve for spray and fuse we leave the ID quite under size so the material doesnt warp during the wetting in phase. The dilema is the most affordable material we can get for the current quote will be about .350" wall thickness during wet in. The sleeve will be 5.625 OD and 13.5" long I am wondering if anyone has had much experience with spray&fuse on sleeves this size?? Most of our previous experince is with smaller diameters and shorter sleeves.
Which brings me too my 2nd question this job is going to be sprayed with a colmonoy 88 and will see low ph solutions(either bleach or brown stock) I am wondering if maybe a hvof applied coating would work in this instance???? in resistance to the enviroment and ease of application.
Any help is always appreciated
Brent

[HVoilF]

We do spray a lot of pump sleeves for the Oil Industry,most of them with Colmonoy 88 HVOF using the JP 5000 gun. We do spray some 12 to 15/1000" coating thickness(after machining thickness) and then we seal it (phenolic sealer) We get some 700 to 800 Vickers hardness and it work quite well. We would suggest to spray at some 60-70 RPM for this diameter,preheating at some 80-90ºC). We feel that this coating is good enough in the "as sprayed " condition. Of course if you fuse it you will get a better,harder (some 80-100 Vickers improvement),better wear resistant coating,but to fuse a coating is always a hard job to do!

[Vijay Deshpande]

Dear Brendt,
While carrying out this type of jobs, we usually pack them with qwartz sand and it works extremely well.
Vijay

[djewell]

There are many other materials you can use to protect your sleeves from low ph solutions, and they do not require fusing. Application by HVAF/HVOF will give you high hardness and high density without the risk of thermal deformation.