I used Pex cinch clamps on my baseboard hot water heating and system. The system is about 7 years old. I have had 2 different clamps break and the water dripped on my floor. Are the cinch clamps the type to use or should they all be changed out for the copper compression type? I’m thinking the expansion of the SS clamp is different than the fitting causing them to split.
Plumbing – Why are Pex cinch clamps breaking
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I am a professional plumber and I have been using PEX tubing for 20 years and I am also manufacturer-certified to do so.
The only time I've ever seen this green color in PEX tubing it was algae. The pipe was a cold water supply line that was wrapped with heat tape and pipe insulation, and run above ground underneath my camper. When I removed the pipe it had algae growth along its whole length.
However, the algae will not stick to the pipe. When you kill it, it will just wash away out through your faucets; just make sure you remove your aerators in order not to clog them.
- Shut off the water supply line to your water heater.
- Drain some water out of your water heater from the drain valve.
- Disconnect the supply line from your water heater, so you can pour your bleach in from there.
- Reconnect your water heater and run hot water out all your faucets until you can smell the bleach.
- After letting it sit for a sufficient amount of time, flush all the water out of your hot water pipes and water heater until no more bleach is detected.
This will kill your algae, but you may still have it inside your pipes. You might need to tap on the pipe to knock it loose before flushing.
In my case I drained the pipe and the algae dried up and fell from the pipe. Or you could remove and replace the affected area.
First of all the information I'm providing is based on my local codes, your local codes my very.
Quick Answer
You will need to feed the lower floor manifolds with 3/4" PEX inlets and 1/2" outlets. No manifold would be required for the upper bathroom as only 1/2" PEX is needed for both the hot and cold, just tee off the 1/2" lines to feed the sink, tub and water closet. All individual fixture runs would be 1/2" as well.
Detailed Answer
Using manifolds and running to each fixture individually is called a homerun system. This can be less labour but may have a higher material cost. It all depends on how far the groups of fixtures are from the manifold. This method is typically used when the pipes are run through the slab.
Depending on the location of the fixtures, you may want to look at a truck and branch system. This is were you would run two mains and branch off to the fixtures as it passes them. The mains would get smaller as the fixtures are taken off.
Water lines are sized so that the velocity within the pipe is kept below a set point. This is to limit the wear and tear on the pipe material. Different materials can handle different velocities at different temperatures. The max velocity for copper and PVC is 5ft/sec for cold and 4ft/sec for hot. PEX pipe can handle a maximum velocity of 8ft/sec for both hot and cold.
Fixture units (FU) are given to typical fixtures. A FU is a design factor that is used to represent the typical requirement of a particular fixture (it is not a flow rate but).
Fixture Units for Private Use Fixtures (no flush valves):
|--------------------------------------------------------| | Fixture | Hot FU | Cold FU | Combined | |--------------------------------------------------------| | Bathroom Group | 4.50 | 4.50 | 6.00 | | Bathtub/Shower | 1.50 | 1.50 | 2.00 | | Clothes Washer | 2.25 | 2.25 | 3.00 | | Dishwasher | 3.00 | - | 3.00 | | Hose Bib | - | 7.00 | 7.00 | | Kitchen Sink | 2.00 | 1.50 | 1.50 | | Water Closet | - | 3.00 | 3.00 | | Lavatory | 0.75 | 0.75 | 1.00 | |--------------------------------------------------------|
The above table lists the common residential fixtures and their FU. You can see that a bathroom can be considered one group and has a lower FU then the sum of it's parts. This is because they are typically used by one person at a time so it is unlikely that all fixtures will be running at the same time.
Once we have the FUs, we can look up a sizing chart that will tell us the maximum FUs that a pipe of a set size and material can handle while staying below the maximum velocity. You can view these tables in the Domestic Water Sizing Tables (For Small Buildings) section below.
Based on this information, we can size your distribution system as follows for PEX:
|----------------------------------------------------| | Fixture Group | Hot | Cold | | | FU Size | FU Size | |----------------------------------------------------| | Upstairs Bathroom | 4.50 1/2 | 4.50 1/2 | | Downstairs Bathroom | 4.50 1/2 | 4.50 1/2 | | Kitchen | 4.50 1/2 | 1.50 1/2 | | Half Bathroom | 0.75 1/2 | 3.75 1/2 | |----------------------------------------------------|
So you can see that the pipes feeding each group of your fixtures will only need to be 1/2". Each individual fixture would also be 1/2". However, depending on how the groups of fixtures are located relative to each other, you may require 3/4" pipes to feed more then one group. The total FU of your house is 14.25 Hot FU (3/4"), 21.25 Cold FU (1") and 28.00 Combined FU (1"). The Combined FU is used to size the section of pipping from the cold line into the house to the hot water tank. Don't be alarmed that the cold and combined are sized at 1". This is due to the allowance of the hose bib, which our code now calls for 7 FU. This is too high and has been causing issues in large buildings with hose bibs on small decks, in that the lines are oversized and do not properly flow, allowing for growth in the water. Without the hose bib, your cold is only 3/4".
Domestic Water Sizing Tables (For Small Buildings)
- Minimum pressure available - 60 PSI at property line. (Greater acceptable).
- Pressure reducing valve set at 60 PSI minimum.
- Pressure loss for meter (3 PSI), maximum building height 25 ft. (10.82 PSI)
- Minimum 0.115 PSI for friction loss. If less than 0.115 PSI, system must bp fully engineered by detailed method or there will not be sufficient water to supply the fixture.
Pipe Flow Velocity Table For: Copper & PVC:
|---------------------------------------------| | Pipe Size | 5ft/sec (cold) | 4ft/sec (hot) | | | GPM FU | GPM FU | |---------------------------------------------| | 4" | 186.65 850 | 149.32 600 | | 3" | 106.16 400 | 84.93 295 | | 2-1/2" | 74.37 245 | 59.50 170 | | 2" | 48.23 120 | 38.58 81 | | 1-1/2" | 27.72 46 | 22.18 34 | | 1-1/4" | 19.59 29 | 15.67 22 | | 1" | 12.86 18 | 10.29 14 | | 3/4" | 7.54 9 | 6.03 7.5 | | 1/2" | 3.64 3.5 | 2.91 2.5 | |---------------------------------------------|
Pipe Flow Velocity Table For: PEX, PE, PB, CPVC & Ductile Iron:
|-----------------------------------| | Pipe Size | 8ft/sec (cold & hot) | | | GPM FU | |-----------------------------------| | 4" | 300 1800 | | 3" | 170 750 | | 2-1/2" | 152 500 | | 2" | 78 265 | | 1-1/2" | 44 102 | | 1-1/4" | 30 54 | | 1" | 20 30 | | 3/4" | 12 17 | | 1/2" | 5.8 7 | |-----------------------------------|
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Best Answer
I have had those rings break on me also. The adjustment of the tool has to be just right. I don't use them anymore. I would use the copper compression ring.