PDA

View Full Version : Vacuum pump?



maplenutter butter
05-01-2017, 03:24 PM
Would this pump work for vacuum on my lines and if so, how many taps do you think it could handle?
CL
minneapolis >
dakota/scott >
for sale >
tools - by owner
post account
1
reply x prohibited[?] Posted 3 days ago
◀ prev ▲ next ▶
favorite this post High Vacuum Pumps - Welch/Varian - $325 (Savage) hide this posting
image 1 of 7
1
1 2 3 4 5 6 7
Welch 1397 Belt-Drive Vacuum Pump $325

This is a high CFM vacuum pump with very few hours on it since rebuild. I used it for hobby neon fabrication as my primary vacuum pump without any additional diffusion pump.

It is in nearly pristine condition internally and has never been used for condensables. Pumping rate is 17.7CFM (500 liters/m) at atmospheric pressure. Ultimate rated pressure is .0001 Torr, although achieving this level of vacuum reliably requires frequent use on a sealed system to minimize atmospheric contamination.

The motor is 1HP and prefers to be alone on a 15A 120v circuit to avoid blowing breakers at first when moving large volumes of air. I had two of these pumps, and this is the better of the two. The one I am keeping had previously seen some moisture so I am keeping that for vacuum casting, which can be corrosive.

Uses include neon/vacuum tube fabrication, a central laboratory vacuum pump, or large scale vacuum forming, bagging, or casting.

These pumps are $5k plus new and usually more than half that for rebuilt. You will need two people to lift into your vehicle.

Manual included.

$325



Varian HSA Diffusion Pump $150

This can be used with a mechanical backing pump to reach lower pressures than possible with a mechanical pump alone. There are no moving parts - just a heater.

This pump was removed from a helium leak detector and is in clean working condition. It has a 120v, 350watt heating element and uses silicone diffusion pump oil (not included). A cooling blower and some miscellaneous tubes are included. What appears to be rust in the photo is not - the cooling fins are copper.

Note: This pump will not produce a vacuum by itself - it needs a mechanical roughing pump such as the Welch 1397 ahead of it.

$150

Both pumps for $450

Cash only.

Contact me via the link above with a message and your phone number, or use my Google Voice at show contact info and leave your name, phone number, and message. If I can't answer I'll get back to you asap. No text, please.


Keywords: Vacuum pump, diffusion pump, neon lighting, vacuum forming, vacuum bagging
do NOT contact me with unsolicited services or offers
post id: 6108362678 posted: 3 days ago email to friend ♥ best of [?]
safety tips
prohibited items
product recalls
avoiding scams
© CL help safety terms about desktopvacc

unc23win
05-02-2017, 10:29 AM
I like to size my pump for 50 taps per cfm some producers use 100 taps per cfm. So 17 cfm is ranged from 850-1700 taps. There are variables that come into play not all pumps are rated the same, but most are. You may be able to find a graph showing the performance curve often cases (but not always) the highest level of vacuum can only be made when the required cfm is lower than the pumps rating. A tight well maintained leak free system will also help the pump achieve higher vacuum. I believe the Welch pumps are pretty good and from a well known company.

morningstarfarm
05-04-2017, 10:02 PM
For that price i would jump on it...i have several of them and they are great...

jimmygarison
08-09-2017, 03:09 PM
Hi, i am jimmy ,Becker offers a variety of vacuum pump types that cover a wide range of operating pressures from atmospheric to 0.5 torr (29.9 in.Hg).
These includes :
oil less dry
oil flooded rotary
oil less dry rotary screw