Is the smaller ID on plastic fittings (for pex) "smaller enough" than brass to have an effect on water flow through the pipes? I'm trying to do everything I can to get the most possible pressure and flow out of my system while I'm re-doing things. Plastic fittings price and lack of reactivity to elements in the well water make sense but I've read that their ID being smaller is a downside. Just wanted to hear from other people before making a decision.
Water flow with plastic and brass pex fittings
pexplastic
Related Solutions
PEX labeled fittings are uniform (essentially). You can use any pex labeled fitting with any pex labeled tubing and any pex labeled crimp ring, provided they are all labeled for the same size tubing and the manufacturers literature shows as astm compliant. For ordinary residential remodeling you don't need to be concerned with pressure ratings of the assembly.
Note that PEX labeled components are for use with potable water only, unless otherwise noted in the manufacturers literature (I don't know of any exceptions but they may be out there).
TLDR: Yes, either type of attachment ring can be used. At least in the USA, these products have to conform to standards which make this so. Additionally, some manufacturers specifically state this is the case.
Details:
Primarily, this seems to come down to manufacturing standards.
In the USA, "PolyAlloy" fittings are governed by standard ASTM F2159 Standard Specification for Plastic Insert Fittings Utilizing a Copper Crimp Ring... which states:
This specification establishes requirements for sulfone plastic insert fittings utilizing a copper crimp ring for [PEX] tubing...
Based on that alone, it would seem that these plastic fittings can only accept the copper crimp rings, not the Oetiker-style stainless steel cinch rings.
However, cinch rings are governed by ASTM F2098 Standard Specification for Stainless Steel Clamps for Securing [PEX] Tubing to Metal Insert and Plastic Insert Fittings which states
This specification covers stainless steel clamps ... that comply with F1807 or F2159, and cross-linked polyethylene (PEX) plastic tubing ...
Therefore by reference to F2159 it seems that the cinch clamps are effectively retconned into acceptability for use with polyalloy fittings.
For example, Everflow fittings are documented to be "Certified to ASTM F2159". And here's a marking on a Vanguard Apollo package indicating the same:
Update: I contacted Apollo about this and they wrote:
You may use pinch rings, copper crimp rings, pro crimp rings, and stainless steel sleeves with any of our Poly Alloy fittings.
So at least as far as their products go, there should be no problem. And I think therefore that any of these fittings made to the same standard ought to be fine also.
Related Topic
- Plumbing – Do I expand or crimp pex water line, and why
- Water – Do pex fittings need to be replaced when installing a new water heater
- Plumbing – Would increasing pipe size just after the meter give better flow without increasing pressure too much
- Plumbing – 3/4“ PEX fittings less than 3/4”
- PEX repipe and hot water issues
- Plumbing – What’s the difference (if any) between these two types of PEX-to-copper fittings
- Plumbing – Burying PEX Pipe in the ground
Best Answer
Yes, of course it has an effect. How could it not? One benefit to using PEX is that you can make very long runs with a single piece of pipe without any joints.
But if you have a concern about a specific run, then the solution is to upsize that run to a size that will flow what you need at that location.
You have not provided any specifics in your question, so the best answer that can be given is also general.