How to remove a reducer or a plumbing coupling piece

[Nick F]

Thanks for your confirmation
the video i watched says to apply 4 circles of teflon, hand tight all the way then add 3 turns using a wrench/pliers.
are these the common practice followed in everyday's work?

3 turns after hand tight may be too much - its not that predictable. I hate to say it, but its a "feel" you develop with experience - obviously, this does not help you at this time!

The amount also depends on the materials of the fittings. If made of high strength steel the joint will suddenly get quite hard to further tighten. With brass or aluminum, the difficulty comes on more slowly.

A point to remember is that you may want the fitting to face a certain way. If you are unlucky you will have to choose between tightening by almost a whole extra turn - or backing-off the joint slightly.

I'm sure that other members will chip in with their own recommendations!

 

[Bacchus]

Thanks, i never noticed the difference between tapered and straight threads.

if you look at the photo in post #1, the cold water inlet shutoff is a 3/4 ball valve, i checked several 3/4 ball valve links, they all have NPT threads.

does the 3 way T in your first link also has NPT threads? so actually most plumbing connections on boats have tapered threads, including seacock, strainer, water pump, and water supply lines to faucets? only garden hose are straight threads?

so garden hose connections are sealed with o ring, while the others are sealed with metal to metal contact or teflon tape?

Yes to NPT on winterizing kit valves

Balance... Mostly correct but the common use of straight threads on boats is the thru hull ftg. If you mate that with a tapered thread valve you have a potential disaster ( sinking ) in the making.
https://marinehowto.com/seacock-thru-hull-primer/

 

[Bmarler]

Thanks for your confirmation
the video i watched says to apply 4 circles of teflon, hand tight all the way then add 3 turns using a wrench/pliers.
are these the common practice followed in everyday's work?

Using Teflon alone isn’t a bulletproof method for pipe joints. Getting it tight and also pointed the right direction can be hard sometimes. Plus, if you turn the fitting backwards to line it up the chance of leakage increases. Always better to creep up on lining it up as you tighten. I like to use a combo method.
I use 1 maybe 2 wraps of Teflon, being sure to leave the end threads bare. Then coat with a sealant like rector seal, then assemble. Leaving the end threads bare helps reduce the chance of the Teflon tearing off and getting in the pipes.
Rector seal works great on water lines, I use other sealants for fuel or oil.

 

[RT Firefly]

Greetings,
After learning about Rectorseal on TF, I tend to use it exclusively (without teflon tape). I tend to feel that due to teflon's "slipperiness there is more of a chance of over tightening potentially cracking the fitting. YMMV.

 

[TJM]

I also stopped using Teflon Tape many years ago. When and if any tape gets loose or frayed it will always end up in a pump, nozzle or a filter where it wreaks havoc. Loctite 592 is great for general usage, Loctite 565 works great with Gas and Diesel. Permatex has some good stuff also.
As has been said above, it is a feel more than X number of turns. Teflon tape is also NOT user friendly if having to re-assemble a previously threaded joint.

 

[paulga]

i just noted the hose has straight threads but the copper valves has tapered threads. this is not a concern because the bypass position is only supposed to be engaged for a short period of time?

The link you provided was for a MHT fitting to attach a garden hose female connector. The fitting you mention has pipebthread... actually NPT... national tapered pipe thread whish common household pipe thread / fittings. Look up /:search for various threads you cited and you will learn the differences..while different ones may appear to join together they are NOT compatible and can lead to leakage, breakage & worst case sinking when straight threads are joined to tapered at a seacock.

If you search RV HWH bypass kit you find examples.here is one

https://www.etrailer.com/Accessorie...BvRr6DRXetGw9cREqm5a4fy38X6v_AjkaAh0kEALw_wcB
They come with different length hoses to act as the bypass. Measure the distance between where the valves will be located to figure out what L you need. Emailer is a good source and they have many how to instructions to help if you are still unsure

They b also sell a similar one valve kit for inlet to thevwayer pump. Winterization is EZ as after installation you empty empty the tank, turn the valve, connect the short hose into a jug of pinknandbturn your pump on and open each faucet in sequence to get pink in all faucets / fixtures.
https://www.etrailer.com/RV-Fresh-W...4CkUs6YDqVdF2n4hcieAruA8D2APRxo8aApyeEALw_wcB

If you haven't performed DIY winterization before you may be waybahead to have someone that has experience do it. Best to observe, take notes & video to ensure ability to DIY next time w /o an expensive oversight. It's not difficult once you know what you are doing... fixing freeze up problems are much more difficult, more expensive and very little fun!

 

[Nick F]

i just noted the hose has straight threads but the copper valves has tapered threads. this is not a concern because the bypass position is only supposed to be engaged for a short period of time?

Contrary to the rule of never mixing straight with tapered threads, a female hose connector (straight thread) can be reliably coupled with a 3/4" NPT male fitting. Note that the sealing is achieved by the rubber flat washer.

 

[KnotYet]

Contrary to the rule of never mixing straight with tapered threads, a female hose connector (straight thread) can be reliably coupled with a 3/4" NPT male fitting. Note that the sealing is achieved by the rubber flat washer.

While this may be possible and 'work' for low or no pressure applications, USA
garden hose thread pitch is 11.5 threads per inch and 3/4" pipe is 14 TPI and
so this should not be relied upon to seal and remain tight for anything critical.

It should be noted that in the UK and other UK- influenced areas the hose threads
are 3/4" BSP with 14 TPI. In those places the connection to 3/4" NPT might be ok.

 

[Bacchus]

i just noted the hose has straight threads but the copper valves has tapered threads. this is not a concern because the bypass position is only supposed to be engaged for a short period of time?

Straight threads on the supplied hose fittings are not a concern as those fittings have a rubber insert that provides the seal... not the threads. Also no need to remove / reassemble to bypass. The bypass hose stays in place and you simply turn both valves to bypass.
For The water pump winterization kits the hose gets removed and a sealing cap is placed on the valve unless actually pumping pink into the system.

 

[Capt Ray]

The only thing I will add is a pipe wrench is often used in pairs ... with a second one. So that the threaded joint you intend to loosen (or tighten) is the only thing that turns.

When you torque a pipe wrench on that reducer, you'll want to have *something* gripping the short piece of pipe going to the tank or water heater so it does not turn. It does not look like there is much room there. A "Channel Lock" pliers or even a "Vice Grip" type of pliers may fit.

 

[gilbertpark]

I looked up Rectorseal and it seems to be Teflon Tape or am I missing something? Gilbert

 

[RT Firefly]

Greetings,
Mr. g. Someone here on TF recommended it. It IS Rectorseal but I can't remember the #. 5 perhaps? It's in a tube and NOT in tape form. Perhaps another member can give you the exact stuff.

 

[Larry M]

What RTF said, #5. When we redid our engine fuel system, not one leak with Rector Seal #5. I’ve used it on our potable water system with no issues also. About $5 for a tube.

https://rectorseal.com/rectorseal-no-5-1-3-4-oz-tubes-d/

 

[TJM]

adding to "straight thread vs tapered thread" conclusion.
KnotYet is correct in that the TPI (threads per Inch) needs to match.

I would be leery about threading a tapered male into a straight female, not enough thread engagement, whereas a straight thread into a tapered female has a gasket to seal on.

A wealth of knowledge can be gained by research. For example, in the metric system the thread pitch identification is the dimension in mm from crest to crest and not TPI.
Ex: M8 x 1.25 is a course thread while M8x 1.0 is a fine thread.

I think paul has a Christmas list going of research material. All good stuff.

 

[paulga]

The braided hose stuck on the copper nipple fitting. I tried to wiggle the end, but it only rotates around the nipple, does not come off a bit. Should I use the hose plier here?

The cold supply hose end also stuck.

 

[Lou_tribal]

Use a sharp exacto to split the hose on the fitting, nothing difficult.

L

 

[paulga]

Use a sharp exacto to split the hose on the fitting, nothing difficult.

L

make a split just enough to take the hose off? then cut the split end off? i think the split end will not seal well using a hose clamp.

the hot water hose is long enough but the cold hose does not have much margin

 

[Lou_tribal]

make a split just enough to take the hose off? then cut the split end off? i think the split end will not seal well using a hose clamp.

the hot water hose is long enough but the cold hose does not have much margin

For sure if you split it you need to cut out the split.
But I would remove those braided hose if you can, but that just my opinion. When I got my boat whole plumbing was done with these hoses. One bad thing about them is that they soften when heated. One a warm day after 8h cruise and a warm engine room, one hose popped out of a fitting (even with a clamp) because of water pressure. I was fortunate to still be aboard and to hear some water flowing... Never again this kind of hose will find its way into my boat. Redid everything using pex and very short length of flex hose for end connections.

But this is my experience, do not say this is applicable to your situation.

L

 

[paulga]

Are these hoses measured by id or OD?
I prefer spring style hose clamp

I'm going to try heat gun and hose pliers, with spliting as last resort.

For sure if you split it you need to cut out the split.
But I would remove those braided hose if you can, but that just my opinion. When I got my boat whole plumbing was done with these hoses. One bad thing about them is that they soften when heated. One a warm day after 8h cruise and a warm engine room, one hose popped out of a fitting (even with a clamp) because of water pressure. I was fortunate to still be aboard and to hear some water flowing... Never again this kind of hose will find its way into my boat. Redid everything using pex and very short length of flex hose for end connections.

But this is my experience, do not say this is applicable to your situation.

L

 

[Comodave]

The braided hose stuck on the copper nipple fitting. I tried to wiggle the end, but it only rotates around the nipple, does not come off a bit. Should I use the hose plier here?

The cold supply hose end also stuck.

View attachment 144402

Try some heat and it may soften enough to get it off. I also like PEX rather than this hose.

 

[paulga]

I measured the o.d. of the hose around nipple is 18.6mm, should I use 18mm spring clamp?

Try some heat and it may soften enough to get it off. I also like PEX rather than this hose.

 

[paulga]

Is the hose in my photo called flex style?
What does pex and flex connection look like?

For sure if you split it you need to cut out the split.
But I would remove those braided hose if you can, but that just my opinion. When I got my boat whole plumbing was done with these hoses. One bad thing about them is that they soften when heated. One a warm day after 8h cruise and a warm engine room, one hose popped out of a fitting (even with a clamp) because of water pressure. I was fortunate to still be aboard and to hear some water flowing... Never again this kind of hose will find its way into my boat. Redid everything using pex and very short length of flex hose for end connections.

But this is my experience, do not say this is applicable to your situation.

L

 

[Nick F]

Are these hoses measured by id or OD?
I prefer spring style hose clamp

.

Hoses are measured by ID. If the OD is 18.6mm it is almost certainly "1/2 inch" hose.

Not sure what you mean by a spring style clamp.

 

[paulga]

Hoses are measured by ID. If the OD is 18.6mm it is almost certainly "1/2 inch" hose.

Not sure what you mean by a spring style clamp.

spring style clamp does not loosen over time. it is more commonly seen in auto parts.

when I started to remove the screw clamps on the hot water heater hose, there was no tension at all. the screws were not tightened. there was no leak only because the hose are already stuck to the nipple.

the nominal diameter of a spring clamp is measured in o.d.

well, it is said to seal better on a smooth body barb, e.g. a car radiator hose fitting. so it may not seal well here

 

[paulga]

Try some heat and it may soften enough to get it off. I also like PEX rather than this hose.

does the heat gun melt the hose?

if you look at the cold water hose at the bottom, it touches the large engine exhaust hose, so the heat wave will blow on the exhaust hose for sure. will this damage the hose?

 

[Lou_tribal]

does the heat gun melt the hose?

if you look at the cold water hose at the bottom, it touches the large engine exhaust hose, so the heat wave will blow on the exhaust hose for sure. will this damage the hose?

What he meant is heat the hose so it soften and so you can giggle it a bit and remove it. The intend is not to melt it.
And your exhaust hose is made to withstand more heat than this.

L

 

[Comodave]

Do you have a heat gun? If not buy one. They are useful for various things. You heat it just enough to get the hose off, not enough to melt it. Heat it a bit and try removing it, if not heat a bit more and so on. After you do this several times you will get a feel for how much to heat it. This type of hose gets hard and may not seal up again and you may have to replace it. I just had to replace one just like it due to not resealing the second time.

 

[paulga]

I have a dewalt heat gun and am learning how to use it.

yes, i noticed the end is hardened around the nipple. may have to cut the end anyway if a clamp does not seal. the access is difficult to lay hands on the other end from the copper tubing (to disconnect is even more difficult), so I would not try replacing the hose at this time

Do you have a heat gun? If not buy one. They are useful for various things. You heat it just enough to get the hose off, not enough to melt it. Heat it a bit and try removing it, if not heat a bit more and so on. After you do this several times you will get a feel for how much to heat it. This type of hose gets hard and may not seal up again and you may have to replace it. I just had to replace one just like it due to not resealing the second time.

 

[Comodave]

Difficult access is known as working on a boat…

 

[Lou_tribal]

Difficult access is known as working on a boat…

Amen

L