Meaga press for steam

Steve_210

Mega press for steam.
Starting to see a lot on black pipe
I know its rated well above my working temp and pressure.
Has anybody had any problems planning on using on larger apartment buildings

ScottSecor

We have used it on steam numerous times, no issues to date.

Steve_210

Thank you I’m starting to see a lot more it’s all low pressure steam

pedmec

Only on repairs. i've always been this way with new products. I like to wait a little to see what happens. i do have a couple of concerns and they are in regards to the pressing of the fitting. the fittings are always twisting and turning and once its pressed its almost impossible to correct. especially on the header which you want draining toward the equalizer. Always make sure your pitch is correct so the condensate wont kill the steam.

The other issue is Viega says that the condensate will eat up the carbon steel so it shouldn't be used on condensate returns. i just had to replace underground piping on a two pipe system which required ripping up the hardwood floors and replacing about 100' of schedule 80. it would have been a perfect application as getting wrenches in there were a problem. A no go for me as i don't want to be around when it leaks again. And I won't use copper on condensate returns either as i feel it takes away from the trade. I can't help myself, its just how i feel. Hate seeing copper on steam.

SteamingatMohawk

Technically it is allowed for temperature and pressure, depending on the gasket material used.

Personally and not being in the trade, I don't like the mechanical pressure boundary connections invented in the last few decades, unless they are in an open location that can be monitored.

Thermal expansion and contraction, whether it is in the piping itself (with similar materials or a mix of materials) or in the building can put some stresses on the joints. I realize technology exists to handle that potential movement, but I have no knowledge about what has been considered in the design of the fitting systems.

Check this out. It talks about some of my concerns.



https://info.viega.us/blog/how-to-use-megapress-fittings-for-steam

Mad Dog_2

Not a fan..sorry...Megapress on Natural Gas....no way...Not in my house.  Mad Dog 🐕 

Steve_210

Thanks I really only want to use it for repairs. Just trying to get the heat back on in the middle of winter.
BTW I like to use copper below the waterline, but never above the waterline of the boiler.
At least that’s my opinion you can power flush it with confidence not be afraid you’re going to rupture the line someplace. But of course that’s only on old black returns.
I just think the copper will not rot out on the condensate return.

Mad Dog_2

Megapress on Steam I can live with..Mad Dog 🐕 

Steamhead

SteamingatMohawk said:

.......Thermal expansion and contraction, whether it is in the piping itself (with similar materials or a mix of materials) or in the building can put some stresses on the joints. I realize technology exists to handle that potential movement, but I have no knowledge about what has been considered in the design of the fitting systems.

This.

EBEBRATT-Ed

Not a fan of either one. Stuff is expensive. But that is off set by the labor cost. I just don't like having to scrap a bunch of expensive fittings when you have to replace something and everything is close coupled.

I can remember Propress started being used in the shop I worked for around 2003 ?? and I am sure it was out before that and definitely was overseas.

The first and only prepress gun we had was a corded model and pretty heavy with the 2" jaws on it and very long and no swivel head. You could back yourself in a nasty corner if you didn't pay attention. Had plenty of power though you had no doubt when it was crimped. they said at that time 50 years on the O rings.

clammy

I recently looked at a re pipe which the contractor had used mega press on the header including the equilizer ,Hartford loop tee and back to the boiler . Unfortunately 3 of press press joints where leaking and had some quite large cauliflower growing aside from leaking when operating . Of course it was piped terribly so it may have been worse had it not been so easy w the mega press but they still got it wrong anyway . I think w what they used in material cost wise they could have piped it in cast iron and used both tappings and it been about the same price . They of course would not return for what ever reason and I didn’t get the job for the repipe the boiler and 3 steam mains repairs and re pitching of the mains among a lot of other neglected issue . Same ole same ole under performing systems and people live w it or replace it w a better zero maintance just replace system . As for mega press I guess for a emergency repair or in wall repair ok but to do a steam boiler nbp in it ,I would think it would be cost prohibitive when it comes to say a 3 or 4 tee better yet reducing tees ouch . Biggest hang up is the cost and waste being zero is reusable just to the recycle if lucky .
Peace and good luck clammy

Steve_210

Yeah, I would really only use it for emergencies. Get the heat back in the dead of winter. Thanks.

mattmia2

You need the ability for the boiler and the header to expand independently so you would at very least need to use some threaded fittings to allow that.

realliveplumber

Mega pressed joints have all kinds of rotational movement in them after they are pressed. Its way more than a threaded joint . Some can get 10 to 15 degrees.

kinda scary how much. But they dont leak.

mattmia2

Very scary. Did i mention I need to replace the radiator in my car because it is leaking between the tank and the core? I'm pretty sure it is because they o-ring has fossilized over the past 22 years.

dko

The potential issue with megapress for novices is not leaking, it's the deflection. Getting it all level and pitched the way you want with a single press is a pipe dream. It's like playing a game of billiards pressing and repressing sequential fittings on the proper sides/angles to get the level and pitch you were aiming for.

And if you mess up, gotta cut it all out! But with the cost of the fittings, many will opt for the "ehhh its good enough."

ethicalpaul

realliveplumber said:

Mega pressed joints have all kinds of rotational movement in them after they are pressed. Its way more than a threaded joint . Some can get 10 to 15 degrees.

kinda scary how much. But they dont leak.

Threaded steam joints have no movement in them. Anyone who has tried to remove a fitting knows this!

BenDplumber

Holy ****! All these years installing swing joints in mechanical piping and you discovered that they aren't needed because your rotational force can't remove them? Come on man. Regardless they are required by AHJ, MEP engineers, fire suppression contractors, medical and compressed air contractors and most manufacturing engineers. We're talking about small movement in more than the couple of joints you disassembled.

ethicalpaul

The extra "distance" introduced by a swing joint does provide more "flex" to the entire run, but it's obvious--if the joints were ACTUALLY sliding during every heating cycle, then they would be easy to disassemble. The joints are as good as welded. You named a lot of different uses of joints, I am talking about steam joints, here on the Strictly Steam forum.

And yes I haven't disassembled very many compared to you pros. So I'll ask you: the joints you have disassembled--you believe they were moving? Look deep within yourself (and not just repeating things you have heard said for years) and you know.

STEAM DOCTOR

This is something that has bothered me for years. Do threaded steam joints really move? Why don't they leak from all of that movement? Even if it's not a lot of movement, I would think that years of movements would cause leakage. If we were to draw a very thin line on a fitting and a pipe, perfectly lined up, would they be misaligned after a while? Listen, as long as I am holding a pipe wrench, I will be utilizing swing joints. But just wondering. I am wondering if the reason why copper joints are more prone to leaking, is because the copper heats up much quicker, and expands more than then the thicker steel and iron pipe and fittings.

STEAM DOCTOR

Is there a difference between low pressure steam and high pressure steam? Low temp and high temp?

STEAM DOCTOR

realliveplumber said:

Mega pressed joints have all kinds of rotational movement in them after they are pressed. Its way more than a threaded joint . Some can get 10 to 15 degrees. kinda scary how much. But they dont leak.

Will this amount of movement contribute to the deterioration of the o-ring? One of the benefits of press over shark bites, is that shark bites move while the Press fittings do not.

ChrisJ

STEAM DOCTOR said:

This is something that has bothered me for years. Do threaded steam joints really move? Why don't they leak from all of that movement? Even if it's not a lot of movement, I would think that years of movements would cause leakage. If we were to draw a very thin line on a fitting and a pipe, perfectly lined up, would they be misaligned after a while? Listen, as long as I am holding a pipe wrench, I will be utilizing swing joints. But just wondering. I am wondering if the reason why copper joints are more prone to leaking, is because the copper heats up much quicker, and expands more than then the thicker steel and iron pipe and fittings.

My opinion is they do not move.  The pipe flexes like a leaf spring but that's about it.  That flex in the pipe can be a huge deal though.


I'm not sure how a binding connection like NPT could move back and forth even a tiny amount 300,000 times over 80-100 years and not be completely destroyed let alone not leak.


That's my opinion. 

dko

EDIT

realliveplumber

STEAM DOCTOR said:

realliveplumber said:

Mega pressed joints have all kinds of rotational movement in them after they are pressed. Its way more than a threaded joint . Some can get 10 to 15 degrees.

kinda scary how much. But they dont leak.

Will this amount of movement contribute to the deterioration of the o-ring? One of the benefits of press over shark bites, is that shark bites move while the Press fittings do not.

Tough to say, but it might be interesting in the future. . Propress copper, especially the larger sizes, 1" and up, have rotational movement. But we havent seen one leak yet.

EBEBRATT-Ed

No, I agree with @ethicalpaul and others that threaded steam swing joints probably don't move much if at all.

This is why I have some issues with some here who bash welded headers.

It is not the threaded joint movement by itself it is how to install the piping so it will have some flex.

As an example see the attached pipe loop drawing.


The dwg on the left is just a simple pipe loop used when you have long runs of pipe to control expansion.

If I remember Y is supposed to be double x.

First time I installed these was on a 250' run of 2" copper.
I put one loop every 50'. I ran all the pipe in a straight line and soldered it.

Then I made these loops in the vise and soldered all the joints except the last two on the elbows and cut them in.

When I was fooling with these if you stood a 4' piece of copper vertically on a floor and pushed down on it would it move? No.

Now try the same thing with one of the pipe loops. You can easily expand or contract the loop buy 1/2" with just slight hand pressure.


Looking at the two boiler drawings the top one has no swing joints and the header is in line with the riser tapings. No good for many reasons.


The bottom dwg has swing joints but maybe more important is that the header is offset from the riser tappings. Its just like a pipe loop.

And a lot depends on the size of the pipe your working with and the material






This offset (the more the better) to me could be more important than the swing joints. JMHO

jumper

We need rubber that lasts centuries so that we can just use clamped connections like in our cars and sewers.

SteamingatMohawk

Here's a table of thermal expansion for steel, cast iron and copper at different lengths. In a 3 foot header is isn't much at all, like 1/20 inch for copper to 1/32 inch for steel and cast iron. I don't think it adds much stress to the joints.

For a 30 foot length its about 1/2 inch for copper and 1/3 inch for steel.