Failed low pressure Wika gauge

Maine Vent

My 1-10oz highly touted Gauge Store gauge has apparently failed. It was working fine since November 5 2011. I thought well plugged pig tail, plugged snubber, bad snubber, plugged gauge, no to all the above.



I e-mailed the company to see about warranty info. Valworks says the gauge is not meant for gaseous media. I know steam is first a liquid, then it turns into a gas, then back into a liquid. I sent them back another a reply and in their gauge info it says it measures gaseous media.



Anyone else using this model of their low pressure gauge? I also bought a very expensive industrial 0-30lb liquid filled gauge from them, I hope that this gauge is reliable.



Thanks





Low Pressure Gauge 2.5", 0-10 OZ/SQ.IN.



Stock #: 33009

Brand: WIKA

Series: 611.10

Mfr Part #: 9851771

Rod

Have a 0-3PSI Wika Gauge

Hi- I suspect you just got a bad gauge. Did you fill the pigtail with water before installing gauge? The gauges are only good to 140 degrees but usually work okay as long as there is a pigtail. I looked at your pictures and it looks like there is plenty of pipe length so that the gauge would remain cool enough. Yes it says they are okay for gaseous.

- Rod

Hap_Hazzard

Same here.

I also have a 0-3 psi gauge. I got it at the end of October. I didn't know about the temperature rating when I got it, but I don't see anything in that pressure range that has a higher rating.

ChrisJ

gas

While the gauge may be rated for gaseous media it may be moot.  When I removed my 3psi WIKA gauge last night to calibrate it without the vacuum of the pigtail interfering I found the entire length of pipe right to the gauge was filled with clean cool water.



The pigtail blocks the steam so you are either measuring water pressure which the steam is pushing against,  or cool air pressure from the steam pressing against water pressing against air trapped between the pigtail and gauge.



Phew!   Either way, you are NOT measuring "steam pressure" as far as they are concerned.  If you say you are, you are going to mislead them and they will not replace it.

crash2009

Bad gauge

The steam never goes past the coil.  Above the coil is always room temperature.  

Maine Vent

Reply from Valworx

This e mail is from Andy cus



Good Morning Mark,



Steam exceeds the Maximum Media Temperature of 140 degrees Fahrenheit for this gauge. Even with the use of a siphon to try and separate the water from the steam in this application it is possible that the moisture and liquid is still entering this gauge. This gauge will not work with any type of liquid. Sorry, we do not offer any type of gauge to measure pressure in this type of application.



Thank You,Andy Bowers

andy.bowers@valworx.com | 704-987-9803 ext 209

Valworx Inc, 18636 Northline Dr, Cornelius NC 28031 USA

order online: valvestore.com | gaugestore.com | regulatorstore.com







-- So now I guess we all should question these Gauge Store pressure gauges. I am looking at other dedicated low pressure higher temperature gauges from Ashcroft, and Delta.I'll keep you up to date on better gauges. Are these Gauge Store devices in code compliance especially the 0-30lb gauges?



Thanks All good replays

ChrisJ

liquid

I don't know, if the gauge says it cannot work with liquid than I'd say that is why it failed.



The 3 PSI Wika gauge can work with gas or liquid as long as its 140F or cooler.

WIKA

Reply from WIKA

Hi Maine Vent,



Capsule gauges are not meant to measure liquids. When the steam condenses in the siphon, it turns into water and this is what the gauge is measuring. You should use a standard Bourdon tube gauge, such as the WIKA  232.53 or 232.54.



Hope this helps!

Rod

How You Mount the Gauges /Controls is Important!

Hi- I'm assuming that WIKA is with WIKA Gauges and I would first like to thank you for replying.  We really appreciate your input!.

  As we want to measure very low pressure steam, the model gauges you mentioned are a bit on the high side for our application.  The models most of the steam guys use.is either the  0-3 PSI gauge   ( Wika #  33020) or for the Vapor Steam Systems, the even lower pressure -  0-15 ounce gauge  (Wika #33010 or 33013)



I have a 0-3 PSI (33020) and after several years of operation haven't had any problems with it.  However I do think it is VERY important to mount it on a vertical pigtail (see attached drawing) and have the control and gauges mounted high so that any water getting near them drains immediately away.  Having them high means they are reading the pressure of the "slug" of air between the gauges and the water in the pigtail. The extra height also dissipates any heat in the piping.  Just a thought.

- Rod

ChrisJ

3PSI WIKA gauge

I would also like to point out the gauge that Rod mentioned model 33020 says it is rated for medium fluid on the spec sheet.



http://www.indautomation.com/pdf/wika/61110.pdf



As I said when I unscrewed mine to calibrate it without it connected I found a small amount of clean water in the connection.  I thought nothing of it as the gauge says its fine with liquid. 



So is warm liquid a problem with this gauge even though the data sheet says its not?





Rod, though its not quite the same as your picture I think my configuration should also provide decent draining, no?

Rod

Gauge Mounting

Hi Chris- Your gauge mounts look fine. All I'm saying is to mount the gauges/controls well above the boiler's waterline and make it so any water has to go a reasonable vertical distance to get near the gauge therefore any that does will drain back immediately.. Use a bottom mount gauge as they drain better. (The gauges that come with the boiler are quite often back mount which is okay as they have an internal siphon (pigtail)  to protect them.)  You see some pretty funky gauge installations from time to time like one mounted on the LWCO on a very short pigtail  The best gauge set up has to be Slantfin which has ports for the gauges/controls on the top of the boiler.

- Rod

crash2009

How's this for "Funky"

I have my 611.10 mounted at the end of an antler to measure the backpressure of the main.  The Hoffman Twins let me know when the steam gets there, sometimes it gets there fast.  I would think a gauge would get more abuse up there.  You know, condensate flying down the main and smacking the gauge at the end of the line. 



I am surprised Mr. Wika, that my end of the line gauge continues on and on after getting smacked around day in and day out.  From what you say, it should have died the first day I put it up there.  Maybe a post mortem should be performed on Mr, Main Vent's gauge to determine the exact cause of failure.

Maine Vent

Reply to Rod, Crash, & Chris

I am tending to listen to Mr. WIKA. I will post pics, for you. All was well until the cold weather hit here in southern Maine. This is when the gauge failed. I also have snubbers below the gauges. Maybe the snubbers only buffer pressure and not fluid. I have some other sites that I am inquiring about their gauges.



See below, The gauge is way above the water line, pigtail stays cool up high, cross sections stay cool. I could of gotten a bad gauge??? My point is, Valworx/WIKA will not warreny these gauges when used on a gaseous/liquid steam system.



Your WIKA gauges are basically the same as mine, just different pressure levels.

Thanks Mr. WIKA for your input, and all the other wallies.

crash2009

fair trial before the hanging

I have snubbers on all mine too.  Also we get cold in Michigan once in a while.  My point is if the gauge can put up with the abuse of being at the end of the main, on a snubber, on a 1/4 turn pigtail, Why did your fail in the well protected area that you had it in?  Yours is the first failure I have read about.  All I would ask for is a fair trial before the hanging.

ChrisJ

I don't know

Maybe Mr WIKA probably is right.



But at the same time, my 3PSI gauge is off 99% of the time. I saw no reason to leave a $40 quality made gauge in use when I'm not looking at it.



I don't have a snubber on my gauge but even when it hangs around 0.8 ounces it stays dead calm, no moving now. Before I skimmed it would bounce and jump.

Mark N

Pressure Gauge

What caused it to fail? Was it liquid or was it over pressure? Did you remove the gauge and try try blowing in it and it no longer works. I have the same guage and it has worked fine for 3 years.

Rod

Snubber Problem?

I wonder if having a snubber installed has any connection to the failed gauges?

I don't have a snubber on my gauge and the gauge has been operational for several years.

Mark mentioned over pressure and  this may be a concern. In my case I've been extremely careful not put any high pressure to my 0-3 PSI gauge.

- Rod

Hap_Hazzard

Thanks for the information

Unfortunately, WIKA doesn't make Bourdon tube gauges with pressure ranges less than 15 psi. In fact, to my knowledge, no one does, probably because Bourdon tube gauges simply are not reliably accurate at lower pressures. Their accuracy is also impacted by large temperature fluctuations.



Are there any accessories available that would effectively isolate a low-pressure capsule gauge from the damaging effects of the medium without diminishing its sensitivity to the pressure?



I'm going downstairs to disconnect my gauge while I await your answer.

Hap_Hazzard

If anything

I would expect a snubber to offer some protection, especially a piston-type snubber, as it would isolate the gauge from the medium and buffer rapid pressure fluctuations.



Capsule gauges are more sensitive to overpressure conditions than Bourdon tube mechanisms. It takes a lot more pressure to rupture a Bourdon tube than to expand it to its maximum working pressure reading, but it will definitely mess up its calibration. If your gauge had been repeatedly exposed to pressures higher than 3 psi, you would see that the needle would register below 0 psi at rest. Capsule and diaphragm gauges are less prone to this kind of distortion, but it takes a lot less overpressure to make them pop.

Hap_Hazzard

I might be unfair in doing so, but

I'm presuming pressure guilty until proven innocent. Pressure had means and motive, and I suspect it had opportunity.



It takes less overpressure to rupture capsule and diaphragm gauges than Bourdon tube gauges. The same amount of overpressure that would burst a small capsule or diaphragm will only distort a Bourdon tube, so if you exposed both types to the same conditions, the Bourdon tube gauge wouldn't stay zeroed, but the capsule gauge would be dead.



Notice that the only gauge that failed so far was a 10 oz. gauge connected to a boiler, where fluctuations are more severe. If the mean pressure is already near 10 oz., while the boiler is bubbling like mad, the peak pressures might easily be twice that, and you might not even see that because not all of the movement in the capsule is instantly transferred to the needle.

Rod

Snubbers

I can see where the piston type snubber could be a benefit  The ones I'm familiar with are the (cheaper) porous type and my concern was that they might be retaining moisture. The data sheet says, (Quote) "  Application

Fluid medium, gaseous or dry, which does not clog

connection port or corrode copper alloy.

Example: low pressure pneumatic systems."  so these model gauges should be expected to withstand some moisture.



 The more I think about it, having spikes of overpressure may be a problem. Is anyone who is data logging pressure? If so do you notice any odd overpressure spikes from something like water hammer or main vents closing?  I imagine these could  be more of a concern if you were using a low pressure (ounces) gauge where you don't have much extra scale "room" to absorb an overpressure spike.

- Rod

crash2009

Yea, you are probably right Hap

 Pressure likely zapped it.  I am going to invite Haljo into this discussion.  He has had an 8oz installed for about a year now.  I think it would be interesting to get his input.



spelled the name wrong Haaljo, got the gauge wrong too.  His is a 10oz, even better.

Mike Kusiak_2

Vacuum?

I wonder if vacuum at the end of the cycle may have damaged the gauge. The absolute pressure change when the steam collapses may be greater than the full scale rating or any steam pressure encountered during the cycle.



I messed up a low pressure gauge by applying suction once, as it was not designed to withstand any amount of vacuum.

Hap_Hazzard

Not likely.

I wish I had a good picture of the inside of a capsule gauge to show you (maybe I'll go take mine apart), because once you see how they're made you'd see that a vacuum wouldn't be able to damage the mechanism.



The capsule is just a kind of hollow, flattened disc--or sometimes several of them stacked up like an accordion, or bellows. When pressure enters the capsule, it expands, moving the gauge mechanism. If you sucked all the air out of it, it would only collapse so far, then it would just stop. That's why they can't be used for vacuum-pressure gauges. The needle might deflect a little when there's a vacuum, but there's a hard limit to how far it can collapse.



I see from the TDS that these gauges have a "copper alloy" capsule. I'd need further information about the alloy to be sure, but copper seems less than an ideal material. Not only is it subject to corrosion, but it fatigues easily. Most of the capsule gauges I've seen have stainless capsules.

Maine Vent

I can make the gauge work

By blowing a small amount of air into the hole. Very slowly the gauge will register and move up or down depending on how much breath pressure I exert on it. I saw a nice show on "How It's Made" on how bourbon style gauges are made, good show. I was wondering also about any vacuum that might be working in the boiler. Would't the piston snubbers also protect against any vacuum where the piston gets sucked down into the snubber base?



I have gauge sitting in a bag of white rice, trying to dry it out, IF it was moisture that damaged it.

ChrisJ

MM #67 LWCO

I believe the bellows in the #67 LWCO which holds the float are made from copper. Don't see many of them failing due to fatigue.



I also believe the temperature controls in my 1933 and 1934 GE monitor top refrigerators use copper bellows. Those copper bellows and line were filled with a liquid a lot like a refrigerant and still operate fine 80+ years later.

Hap_Hazzard

Some pictures

These are some pictures of my WIKA gauge. I'm not too impressed with the soldering on the capsule.

crash2009

Great pictures Hap

 The capsule is those two pieces of copper alloy that are soldered together. 

What would pressure damage look like?

What would heat damage look like? 

nicholas bonham-carter

alternative low pressure gauge

maybe if you have the space, a manometer made out of some clear tubing will be the way to avoid the wika problem, and no snubber needed!--nbc

Hap_Hazzard

What would damage look like

Not sure what heat could do to it. It's hard to imagine how even direct, live steam could do any damage to the capsule. If you could steam apart a solder joint, we'd all be in trouble. but pressure in a closed vessel makes it burst at the weakest point, which would be the solder joint. In this gauge it probably wouldn't even be visible. Over time the solder probably develops stress cracks even under normal conditions, but overpressure causes the capsule to distort, and as the solder weakens at the points under the greatest stress, the distortion is exaggerated and the damage accelerates until a breech occurs.



It's possible this was designed this way as a safety feature. You haven't lived until you've seen a Bourdon tube gauge blow, but capsule failures are a lot less dramatic. This one probably tends to fail without even damaging the halves of the capsule, so you could solder it back together and be back in business.



I think I'm going to put mine back on, but I'm going to put it on a ball valve so I can turn it off when I'm not looking at it.

ChrisJ

solder

Solder as a saftey feature? Maybe but how would it fail on a residential steam boiler.



What is the lowest melting point of any solder, 360-370F?  If his boiler was producing 360F steam then his pressure was certainly too high for my liking.  I could see solder failing if it wasn't done properly.  As far as pressure look at any plumbing, soldered pipe handles 100+ PSI without any problem when soldered properly.



Stress cracks shouldn't happen if the peices were clean, fluxed well and pressed tight together when soldered.  If there was a large gap then sure, but thats poor workmanship.  Those flanges should have had solder all the way to the inside edge, it shouldn't have been able to flex \ bend \ twist.





In your third picture, it looks like there is a hole in the edge of the capsul, is that true?  Its not near where the two halfs meet either.

Hap_Hazzard

It doesn't need to melt.

A thin bead like that can be pulled apart pretty easily.



That's not a hole; it's just a shiny spot. It still works fine.

ChrisJ

Different gauge

I'm currently modifying how my WIKA 3 psi gauge is installed by adding some height to the piping.



I'm curious why not useone of these Ashcroft gauges instead?  They have a 3PSI gauge that says it can handle any media which is not corrosive and they are rated to 270F.  It wouldn't need a siphon and I'd think we would be seeing actual steam pressure then.



Right colum in this PDF.  They seem to be around $50.

http://www.coleparmer.com/Assets/Catalog_Pdfs/0910_PDF/R_01380.PDF

Hap_Hazzard

Good find!

I bow to your superior search skills. I'd be using one of these if I'd known about them!



In fact, I think I'll get two. The R-68930-00 looks like it would work for gas manifold pressures. (For some LP burners you'd need the R-68930-01.)



Thank you, Chris!

ChrisJ

gauge mod

Hap-Hazzard,  I hope it was a good find, I guess we are going to find out.





I just raised my gauge up, I think it was always sitting in a puddle of water which was effecting its accuracy greatly.  Today during a 3 degree recovery near the end I went down and opened the valve to the gauge and it still showed a slight vacuum.  Over a period of a minute it slowly started moving up.



I'm thinking it should stay away from most of the water now.

Boiler Talk

Adding devices to the Pig Tail

How many devices per pig tail?  Does adding t's and other things impact the readings on these devices?  What is the impact on the pressure?  

Hap_Hazzard

Depends on the pig. :-)

There's not a real limit to how much you could put on one pigtail. It's more about what you need to measure.



The trouble with pigtails is that they can become plugged, and anything on a plugged pigtail is likely to register 0 psi or something less than the actual system pressure. If your low pressure gauge is on a different pigtail than your limit (be it vaporstat or pressuretrol), and one of them becomes plugged, you'll be wondering why the limit isn't cutting out when the pressure reaches cut-out, or why it is cutting out when your gauge reads 0. If you put it on the same pigtail, it can show you what pressure your limit is seeing. If it's reading 0 when the system is running, and the burners never cycle on pressure, the high pressure gauge, inaccurate as it is, should still give you an inkling that there's something amiss with the pigtail.



So the best arrangement is to have your most accurate gauge on the same pigtail as the limit device that is actually limiting the pressure. If you have a secondary limit (a lot of people keep their pressuretrol when they install a vaporstat, and commercial systems require a secondary), that should be on a different pigtail so it can cut out if the primary's pigtail is obstructed. If the high pressure gauge requires a siphon (a lot of them have internal siphons) then it should be on the same pigtail as the secondary limit.