LOCK UP TYPE GAS PRESSURE REGULATORS

JOHN C._2

I thank you for your input and will post my results when we are fired up.

JOHN C._2

LOCK UP TYPE GAS PRESSURE REGULATORS

INSTALLED 5 LOCHINVAR HOT WATER BOILERS WHICH HAVE MULTI STAGE FIRING VALVES IN EACH UNIT. THE GAS PRESSURE COMING INTO THE BOILER PLANT IS 27" W.C. I OPENED THE PRODUCT MANUAL AND FOUND THE MIN W.C. PRESSURE WAS TO BE @4.5" & MAX 10.5"W.C.
I ORDERED 5 MAXI-TROL REGULATORS FOR THIS APPLICATION. TAKING IT ONE STEP FURTHER I CALLED THE MANUFACTURERS TECHNICAL DEPT. TO CONFIRM THE FACT THAT I COULD ONLY PURCHASE A REGULATOR THAT RANGED FROM 4.5"-12.0". HE TOLD ME WE SHOULD BE AROUND 8" W.C. BUT NO MENTION OF LOCK UP TYPE REGULATORS. ANYONE THAT KNOWS ABOUT
REGULATORS KNOWS WHAT HAPPENED. WE HAD 27" W.C. WHEN THE BURNER SHUT DOWN. NO MENTION OF LOCK UP STYLE REGULATORS IN THE MANUAL,FROM THE GAS CO., OR THE TECNICAL DEPT. ANY INPUT ON THIS TOPIC WOULD BE APPRECIATED. KEEP UP THE EXCELLENT WORK EVERYONE!

don_52

The Lockup valve...

John,

The lockup valve is doing "exactly" what it's designed
to do, that is to shut off at 120-125% setpoint, okay.

What's happening is when the unit steps to high fire it overshoots hitting the lockup limit or even the high limit
on the gas train.

You need a "straight through regulator" with FIP vent to
run outside + block valves for it and each boiler, it
just needs to meet the pressure + flow requirements.

Fisher Types 66, 299H, 1098-EGR, and 99 are examples,
Maxi-trol also makes them, I see them in my work on
process heaters, oxidizers, etc..

For this arrangement the vent is an absolute must, that said
NFGC,NFPA may require a solenoid / pilot operated valve to
interlock to the fire suppression / alarm system + two or more E-Stops. The latter arrangement is what I'm used to
seeing, interlock to the world.

I'll work up a quick sketch... more later.

db

I'll

JOHN C._2

THANKS FOR RESPONDING

DB,
SO THE REGULATORS THAT WE PURCHASED ARE SUFFICIENT. WE WOULD JUST HAVE TO PURCHASE AN ADDITIONAL VALVE & PLACE IT AFTER THE REGULATOR OR CHANGE THE REGULATOR IN ITS ENTIRETY?
THANKS
JOHN

don_52

Regulators

John,

Replace, that type of regulator can't adjust quick
enough for the step change.

Here's fishers blurb;

This requires the regulator to also react at the same speed. If it does not, it can cause problems with the low- and high-pressure safety cut-outs. If the regulator does not open fast enough it will starve the system of gas and the low-pressure switch will trip. If the regulator does not close fast enough, the high- pressure switch will trip. This high-pressure switch also may be tripped if the regulator does not shut off tight.
For these reasons the regulator chosen must be very accurate, have fast response, and have elastomeric seats that shut off tight.

If I may ask, could you give me the valve model number,
the boiler model number and any info on the incoming
gas line / meter / upstream if known.
The reason I ask is this, I don't want to give you bad /
wrong info, I make these statements tongue in cheek
since I can't see the equipment. The best we may do is
narrow the field and come up with the "right questions"
to ask of the factory come tomorrow AM.
I operate with a different head so to speak, while there
are many similarities there are also many differences.

If you can give me that info, I'll try and get you in the right ballpark. --db

EDIT; What model Maxitrol valve did you order? If you got
the R or RS400, 500, 600 or the 210D, E, G or J, you may
want to look at the Fishers instead.

The type of stuff I'm involved with currently;

Dave_12

Lock Up Regulators

To go a little further, Lochinvar does require on most of their boilers that inlet gas pressure to their units be a maximum of 10.5" wc. With many regulators, downstream gas pressure will creep up to line gas pressure when the boiler is off.

Most regulator manufacturers make both lockup and non-lockup type of regulators. For example, Maxitrol is a common regulator manufacturer that makes both types. The Maxitorl RV61, RV81, or RV91 are not the lockup type and will allow upstream gas pressure to creep by the regulator when the gas burning device is off. Conversely, the Maxitrol R210 series is a lockup type and will not allow upsteam gas pressure to creep by when the gas burning device is off.

Back the the Lochinvar, with your inlet gas pressure of 27" wc, you will need to use the lockup type of regulator. If your building gas regulator at rest would have been only 10" wc, you could have used the less the non-lockup type.

In summary, you have to select the proper regulator based on inlet gas pressure to the regulator, the desired outlet gas pressure at full flow, the maximim outlet gas pressure allowed to the boiler at rest, and the flow rate needed based on the boiler size.

Good luck on this.

JOHN C._2

TO DAVE & db

I WILL POST THE INFO ON THE REGULATORS & THE BOILER MODEL #'S TOMORROW WHEN I GET TO THE OFFICE . ALWAYS A PLESURE TO KNOW THAT THERE ARE GUYS IN OUR BUSINESS WILLING TO SHARE
THEIR KNOWLEDGE. THANKS AGAIN! WILL CONTINUE TOMORROW.

db: thats dome project you are working on. Where is it located?

JOHN C._2

EQUIPMENT ORDERED

THE FOLLOWING IS THE EQUIPMENT THAT WAS ORDERED:
3-LOCHINVAR CHN1801 BOILERS WITH MAXITROL 2" RV91 GAS REGULATORS (MAXITROL VIOR9110 4-12" WC SPRING F /RV91)

2-LOCHINVAR CFN651 PMF9 DOMESTIC WATER HEATERS WITH 1 1/4"
MAXITROL RV81 GAS REGULATORS (MAXITROL VIOR8110 4-12" WC
SPRING F /RV81)

THANKS

db_9

Lockup Regulator

John,

Okay it's now clear what you've got, also, Lochinvar
does suggest the use of a "Lockup Regulators" in
their designer's guide to wit;

A gas pressure regulator is suggested to
help assure proper inlet gas pressure. If
upstream pressure exceeds 6 oz. (10.5
inches of water column), an intermediate
gas pressure regulator, of the lockup type,
must be installed.

Link;

http://www.lochinvar.com/product.asp?cat=B&cls=ALL&prod=CHN0300&ln=CFIIB#

It was unclear as to which direction your problem
was going, that said, Dave's suggestion of the R210
is the appropriate choice.

Link;

http://www.maxitrol.com/PDFs/ms2023.pdf

Note:

Any additional accessories must be ordered
separately.

Link;

http://www.maxitrol.com/PDFs/Mp2037.pdf

Follow the venting guidelines per;

http://www.maxitrol.com/ventingcode.html

Finally a suggestion, if you had gone the last
foot ( read:due diligence ) you would have
found this, okay. The tech support folks at
Lochinvar and Maxitrol get paid to and are
better equipped to field queries such as this,
it goes a little beyond "help".

Anyhow, this should set you in the right
direction, please do call the respective
manufacturer(s) and double check everything.

db