Longevity of Propress Piping

Reliable and proven? Maybe..... It's been around for a while, a lot of knock offs around too, which is a concern, especially of the contractor is try to low ball it. The job's I've seen it used on, there haven't been any issues but who knows in an institutional setting like yours, what longevity, 30-50-75 years, looks like since they are relatively new to the market. The thing I do like about them is that they are a fully mechanical seal, so the installer can see if they have a good seal. Additionally, since it is mechanical seal, any bad joints typically show up immediately at testing and commissioning.
The downside I've seen with soldered joints is since it's only a visual check and service check, there is no good way to know how well the solder joint penetrated and adhered. Even on a visual check, there's typically a blind side that you can't visually verify and can only rely on the service checks to determine the integrity of the soldered joint. With a Propress, you at least know that the die encompasses fitting 360 deg, so the blind side shouldn't be an issue.
The upside to solder, is it's been done for over a century. Trades know it, codes know it, inspectors know it, engineers know it. It's the whole "The devil you know" argument.
I am curious to see how they do hold up long term since they are now seeping into gas piping and other uses commercially and industrially.

The customer may sell that building in a year, so it will be fine for them.

You need to be very specific which brand to use and enforce that. Many unreliable products. Even with a good brand, you are not supposed to use it for pipes with lot of expansion/contraction.

I don't know what life the manufacturer claims. I'd say 20 years. I know the grooved pipe fitting manufacturers say to replace the gaskets after 20 years.

Our firm used to do multi-disciplinary work for the VA at several sites, as well as wrote the first couple versions of the HVAC, Plumbing, and Electrical Design Manuals. The VA has 165-ish major hospitals, and almost 3x the number of Clinics and smaller facilities. So when they have a problem with a new product, it has the very real potential to be HUNDREDS of problems... So they are usually rather conservative in their adoption of new products.

When this type of product came out, they held back a couple years in being approved. Then they allowed it for a couple years. Then they started having problems with failures and leaks on hot water distribution systems, primarily (I think) due to the repeated longer-term thermal cycling. After a few more years, vendors apparently solved that problem, and eventually (several years ago now) the system was approved for both cold and hot water systems.

We have not done VA Projects now for several years. Looking (today) at the current VA Spec 22 11 00 for Facility Water Distribution (available on the VA TIL (Technical Information Library) - which is freely available national treasure of design info, paid for by your tax dollars - highly recommended as an authoritive source for many disciplines), it appears they are now NOT allowed:



Say what you will about government organizations, but the VA usually have valid and proven reasons for every decision they make. IMHO, ignore their recommendations (if you were working for the VA, this would be a requirement) at your peril.

That said, I believe both UPC and IPC both approve these fittings (I would suggest you confirm) - but those organizations are not responsible for what happens when these do fail, and jeopardize the infrastructure and patient care at hundreds of Health Care Facilities around the country.

And THAT said... there is no doubt they are first-cost cheaper.