ABS fittings

[WorBry]

All of the (above ground) plumbing on my AGP is 1-1/2" flexi-hose but I'm looking to hard-pipe a segment of the return line to support an in-line chlorinator.

Couldn't find a particular 1-1/2" PVC fitting I needed in the local pool store, but found the ABS (black) equivalent in a plumbing store. Nipped back to the pool store just to double-check that a stop-valve I was planning to use (with male NPT thread) fitted OK, which it did. Store guy comes over, I explain what I intend to do, and he says you cant use ABS fittings. Why? Because they use different cement. I said, the only thing I'm gluing is the Sch 40 pipe (black) and ABS fittings, and for that I was planning to use the same primer-cement combo - Sluyter 3 primer (clear) and PVC/ABS Transition Solvent Cement (white) - that I use on all Sh 40 plumbing around the home. I asked if it was something to do with the pressure-vaccuum rating, or maybe chlorine-resistance of PVC/ABS welds, and he says, no, as I told you, it's because they use different cement and you should use only PVC fittings. :?

Strange conversation, but is he correct?

 

[JasonLion]

Yes and no. You can join PVC and ABS parts with an appropriate cement specifically designed for that application, like the one you mentioned. But the resulting joint will not meet the pressure rating that you would really want it to meet. Very few ABS fittings are pressure rated at all, and as far as I know, no cement is suitably pressure rated for PVC to ABS joints.

That said, the amount of pressure you are likely to encounter in routine usage is no where near the pressure rating recommended when building pools. So chances are excellent that the joint will hold. But in unusual situations, like a completely blocked pipe getting pumped up to the maximum pressure the pump is capable of, it is quite possible that a PVC to ABS joint would fail.

 

[WorBry]

Thanks. I thought pressure rating, or lack of it, had something to do with. I do remember also when I had a drain leak in the house, the plumber cautioned me not to put too much bleach down the sink as it can weaken the joints. So, probably better to play safe, especially around a chlorinator. I'll look at an alternative configuration with available PVC fittings. Cheers.

 

[WorBry]

PS - just on the subject of hard-plumbing. I seem to recall reading somewhere (maybe this forum) that there should be a minimum distance of straight pipe between the filter return port and the first elbow, to avoid flow impedance. Is that correct and, if so, what should that minimum distance be - with 1-1/2" PVC pipe and fittings, that is ?

 

[jblizzle]

I have not heard of the minimum length of pipe by the filter.

I have heard that some pumps recommend a length of 5-10 diameters of straight pipe entering the pump (although most setups I see on the forums are well under this).

 

[WorBry]

Ah, OK - yes, that is probably what I read. So doesn't apply to the return line then.

 

[WorBry]

Just back to the subject of ABS fittings again.

I was back in the same pool store today to change the large-capacity (9 lb) Olympic in-line chlorinator I was originally going to install for the smaller Hayward CL-100 feeder, which seemed better suited to my needs - also has a built in check-valve in the feed-line, which the Olympic chlorinator doesn't.

This time I spoke to an older guy who had been installing pools for decades. He told me that for relatively straight forward 'above-ground' configurations (like mine), hard-plumbing with Schedule 40 ABS pipe (black) and glued ABS fittings is perfectly OK - just don't glue PVC to ABS, as the PVC/ABS transition cement is not up to it. PVC pipe however should be used for below-ground plumbing and where a required PVC fitting (say a valve) needs to be glued. Screw fittings, obviously not an issue, but make sure they fit well i.e. can screw all the way in and don't require more than a couple of rounds teflon tape for a tight fit. Good advice - it's surprising how many supposedly 'standardized' screw fittings, don't actually fit together that well.

This said I'm still pondering what to do. Here's the scenario.

[attachment=0:128wivub]Chlorinator plumbing 2.bmp[/attachment:128wivub]
[attachment=1:128wivub]Chlorinator plumbing 1.bmp[/attachment:128wivub]

The CL100 is attached to the filter return port with a 6" double 1-1/2" thread connector (not sure if it's PVC, ABS or nylon - but it's grey). Rather than screwing directly to the chlorinator port, I opted to use a union adapter (normally provided with the Olympic chlorinator, but the store sells them separately, and they fit perfectly) on either side, so that I can easily remove the unit for service and winterizing.

So, how best to link up to the pool return inlet? I cant move the filter closer to the pool. Local regulations now strictly require a minimum of 1.5M between the filter and pool wall.

Simplest would be to just hook up hose between the two and have it have it trailing on the ground. This is how it was before, but now there is the added weight of the chlorinator 'limb' hanging off the filter port to consider.

So, hard-piping from the chlorinator down to ground level, elbow to barbed-clamp adapter and then hose up to the pool return would seem a reasonable solution. Question then is, if I used 1-1/2" PVC pipe and connections, would the piping be sufficiently stable to support the chlorinator or would I need to secure it in some way, either to a post or a block on the ground. Don't really fancy drilling into and likely cracking the pavers. For sure, if I used lighter ABS pipe, I think I'd need some additional support.

Guess, I could drop the chlorinator to ground level, but, since it has no base, I'd still have to secure it some way and install a stop-valve up-stream.

Not exactly the most challenging plumbing conundrum, I know, but I'd appreciate any suggestions.

 

[duraleigh]

Isn't the body of a skimmer or multi-port valve ABS? I always thought it was. That is hooked up on a daily basis to PVC pipe without incident using common pvc cement. I can't remember doing anything special when I made up mine and it's been holding for 7 years.

 

[WorBry]

All my connections are presently clamped or screwed, but I guess you're right - many people do glue PVC pipe to ABS pool components with no problems. I dunno, is there some difference in the type of ABS used (high-density??), as compared to regular ABS plumbing fittings?

Note: I edited my previous post.

 

[duraleigh]

Well, IF the multiport and skimmers are ABS and IF I remember correctly, I glued them up with multi-purpose PVC....I think it said right on the can it would glue ABS-PVC but that was many years ago

 

[WorBry]

No, I'm sure you are right.

Maybe this is something that has come down from regulations for larger scale plumbing installations dealing with higher water pressures.

The store guy actually told me that you don't even need to use primer with the PVC pipe-fitting welds, so long as you use specified PVC cement.

A bit confusing, I know, and I probably would have gone ahead using PVC/ABS transition cement (with primer) had I not had these conversations.

 

[bk406]

For the record, there's no such thing as PVC/ABS transition cement, doesnt exist. The can might say ABS/PVC, and thats ok, its the interpretation thats wrong. That kind of multipurpose glue means that you can use it on either PVC or ABS. It's not meant to join the 2 types of plastics together, however. The proper way to join ABS to PVC is with a mechanical fitting. UPC is very clear that you cant join ABS and PVC with ANY type of glue.

Ok, that beng said, I understand that pool plumbing doesnt fall under UPC (it should, but thats a different discussion). So, IMO, if you HAD to join PVC to ABS with glue, on a system that doesnt require inspection and that doesnt fall under UPC, its more than likely you would be fine with using a universal glue.

Oh, and one last thing. PVC ALWAYS requires the use of primer. ABS doesnt need primer.

 

[duraleigh]

That is hooked up on a daily basis to PVC pipe without incident using common pvc cement. I can't remember doing anything special when I made up mine and it's been holding for 7 years.

bk406's post made me go out and look at my connections on the multiport........they are threaded, not glued!! Yikes!! I think I have to withdraw what I said as a result. Perhaps ABS/
PVC connections (glued) are not at all common.....it is apparent I didn't make the ones I thought I did.

(I am not gonna' dig up my skimmers to see what they are but my bet NOW is they are threaded, too.)

 

[WorBry]

Had a look at my skimmer 3-way valve (older Jandy model....I think....I didn't install it) and it's actually CPVC (chlorinated PVC), as are the other well known brands, whereas most other solvent-weld fittings (elbows, etc) are PVC-1.

If I were gluing PVC to CPVC I think be more inclined to use a designated CPVC solvent (with compatible primer), as S40 PVC solvent is not recommended for CPVC in pressurized water systems, whereas CPVC solvent is universally suitable for PVC/CPVC and PVC/PVC welds.

I actually once constructed a frame from CPVC pipe and fittings (DIY camcorder stabilizer) and the darn thing came apart at the joints when glued with PVC cement and primer. Built again using CPVC solvent and it's indestructible.

 

[scooperhsd]

My one comment would be - I would not have the chlorinator RIGHT at the the exit out of your filter - give yourself some space to put a check valve and other fittings (check valve to keep extra chlorinated water away from fittings that don't like it - or a heater someday). That's the way mine is plumbed in, anyway.

As far as winterizing the above ground gear - I simply drain everything so there is no water left in it to freeze and it just sits out all winter (I did take my new pump out this winter).

 

[WorBry]

Yes, I did look into that before - another one of my meandering tales of enlightenment and indecision

reliable-check-valve-for-in-line-chlorinator-t41651.html

A neighbor has a Hayward CL-100 rigged in the same manner, but in his case the filter is just a couple of feet away from the pool wall, allowing the chlorinator to be connected directly to the return inlet with a short piece of flexi pipe. Same with his pump. Unfortunately, my pool was installed after new local regulations were introduced requiring the filter & pump to be minimum 1.5m from the pool wall - apparently to avoid kids climbing into pools off the filter. In fact, when it was first installed, the contractor went over-board and put the filter slab (pavers) about 10ft away with the hoses trailing on the ground. I've now moved the pad closer and surrounded with a gravel bed so I can mow around it. I did consider moving it around a few feet, closer to the pool return, but my wife didn't want the filter and pipes viewable from the house - aesthetics and all that.

One solution I'm considering is putting up a lattice fence/screen around part of the pad (the near side on the photo) and using the wood frame to support and conceal hard-piping - maybe mount the chlorinator on it also. It just seems so precarious as it is now, and I really don't want to be trailing hose across gravel. Same goes for the skimmer-pump line.

One thing's for sure though, I wont be using ABS pipe. From what I've read, the regular 1-1/2 black Sch40 ABS pipe (foam core) found in plumbing/hardware stores is not pressure rated or recommended for anything other than drains. Granted, I could probably "get away with it" in my simple set up, but I don't want to take that risk.

I must say I can appreciate now the appeal of off-line chlorinators in my type of set-up, but I've been put off by reviews saying they are unreliable (clog easily).

Edit: Even if I ditch the chlorinator, I still have the issue of hose trailing on the ground to deal with. From what I've read about flex-pipe, it's important to avoid contact with anything that could cause friction or restrict expansion in hot weather, so supporting it in some way with brackets is probably not a good idea. Don't really want to hard-plumb it all either. Flex pipe does have some benefit in allowing for a little give in the pool wall, putting less stress on the connections. Plus, my pump is not bolted down - not so easy with pavers. So, the only way around it, I can see, is to use sections of PVC pipe in both the suction and return lines so that they can be supported off the ground. Don't really like the idea of having more (flex to hard pipe) connections, but what's better, that or running the risk of wearing holes in the hose ?

On that point, what is more secure - gluing flex pipe into rigid pvc pipe or using a barbed end-fitting with clamp ??

 

[WorBry]

I've read that it's better to use a PVC solvent specifically designed for gluing PVC flex pipe to PVC fittings, as the regular PVC cement can crack. My local pool stores don't have it - one said regular PVC cement is OK !!

I found this solvent at a plumbers store:

Weld-On 795 PVC (clear)

http://www.ipscorp.com/weldon/regularvo ... pvcflexpvc

Contains an elastomer and is stated to be suitable for both flexible and rigid PVC pipe.

The store said you don't need to use primer with it, but I'm thinking maybe yes. I already have pvc/cpvc primer (Sluyter 3 Primer).

Can anyone confirm whether the Weld-On 795 is good?

Edit: Well, after further reading, I'm sure it's the right stuff, as many on-line pool stores list it. Just wondering though, what the difference is between Weld-On 795 PVC and 798 Pool Flex, other than the label and the fact that the former is available in both blue and clear forms?

http://www.ipscorp.com/weldon/lowvoc/po ... aspecialty

From the product MSDS sheets, they appear to have the same composition.

 

[WorBry]

The store said you don't need to use primer with it, but I'm thinking maybe yes. I already have pvc/cpvc primer (Sluyter 3 Primer).

This guide says you should not apply primer to flex pipe, because it over-softens it, only Cleaner. Heck, now I have to get Cleaner as well ???