steam vari vac systems

Unknown

systems should not be bastardized with non electric thermostaic control valves.

Your dunham panel needs to work right, it opens the zone valve in response to the heat balancer, the heat balancer has a steam trap or two that need to work right. the heat balancer can not be near or affected by an open window or door. The heat balancer may need to calibrated. The panel may need to be calibrated.

The zone valve shou;d have a micro switch that turns on the vacuum pump. The vacuum pump needs to be ingood working order. If the pump set is a B or C tank you may need to adjust the discharge valve or replace the suction checks.

Above all you need to do a dead end test on the pump set to make sure it is tight. Oh do not forget the penny valve, it may have been removed, the disc could be dirty and not seating or some one removed it.

And last but not least the differential control may need to adjusted, repaired ir replaced.

And I forgot the steam traps need to work also, oh by the way did some mess around with the orifices on the rad valves.

Oh I just remembered the hvac units on the roof do they have vacuum breakers installed, are the vacuum breakers leaking and letting aair into the system.

Is the condensate temperatures under 160 degrees if not you are in trouble.

I could go on for another hour.

But I GUESS YOU GOT THE MESSAGE.

You need to the what this system is, not it's name.

See your MEPCO reps for info on the system

jake

viv

steam vari vac system

I got the oppurtinity to work on a old steam system with a vari vac attached to it.
The system consists of 2 boilers 140 hp each,vari vac return system 95 % and the rest by gravity to the condensate tank.most of the radiation is equipped with dunham bush therostatic traps,barnes and jones replacement kits..danfoss/honeywell thermostatic operators.i part of the system feeds non vari vac to roof top a-h units.
As i am learning about this system ,i have noted a few things,boiler pressure at 5-10 psi,lots of water hammer,I have replaced a few f&t traps and drained 15 gallons of water out of the 8" condensate main,I am in the process of changing the steam traps onthe rads.

thanks for all your help,where could i find more info on the vari vac system

thanks Dan for your great book the lost art of steam!!

Unknown

on this site, and here.

http://www.mepcollc.com/VV.htm#mepco2

Steamhead

The Vari-Vac

was (and is- they still make it) probably the most elaborate control system for steam heating. When it works, it's great. But like most steam-related things, you have to understand it before you can straighten it out.

There were several versions and levels of Vari-Vac controls available. These changed over the years. If you can tell us what controls are on that system- including the electric steam valves, heat balancers, windowstats, control panels etc- we should be able to identify it.

Noel and I both have catalog info on these systems (thank you Ray Little, Dead Man) so one of us can e-mail you what you need.

To Learn More About This Contractor, Click Here to Visit Their Ad in "Find A Contractor"

viv

thanks guy's I will get more info on the controls and other stuff. viv

fireside

dunham vari vac system

excessive steam coming out of over flow of my vari vac system is it bad traps

nicholas bonham-carter

repost this in the steam section

this is a pretty long-lived post! it will be seen more easily in strictly steam.--nbc

Steamhead

Probably

and you need to fix them right now or they'll kill the vacuum pump. 

oldpipefitter

Veri Vac

I love these systems!  Two decades ago, I had the privilege of working on a restoration of several of these systems at a small university. I say restoration because that's exactly what we did. like restoring an old car. When we were done we could hear the the dead men sing! Saved them literally 10's of thousands of dollars in fuel OVER what the job cost. One of the rare dream jobs one gets if one is lucky. Alas, I have talked to someone who has been out there and they have let these systems return to disrepair. No respect for whats old. My advice..... listen to the dead men as you wander the halls and crawl spaces of these systems. best to you.....

Evilengineer

Looking for parts for the Old Dunham Bush Vacuums...

  I know 20 years ago I would have been still able to buy the Jets, Motors, and Impellars for the VRD 10, 15, 20. Today you can't find anything for these Vacuum pumps. It is sad because the new Models do not stand up to the test as the old ones did. I have 23 Dunham Bush Vacs, all working from 1947 and mostly original except for parts mentioned above, but over the years we have ran out of supplies to rebuild the pumps. I have 2 new models from Mepco, but they don't seem to work as well. Looking for parts or if anyone has any ideas where to find parts for these Vacuum pumps..