Water softener install

[IPDQKWID]

Installing a water softener with carbon filter and pre-filter, it is an Aquasure 64000.
The manual describes connecting the in/out/drain for the carbon filter, using nipples supplied with the unit. Also included are fittings that thread into the valve body, along with washers/gaskets. These fittings have a somewhat flat front end where the threads start, presumably for the gasket to seal against? The nipples do not have that.
My question - plumbing with PEX - do I really need the male x female, followed by a male x male nipple, and then whatever pex adapter I might use?
Included a couple pics if you have any useful tips.
Thanks.

 

[Reach4]

Your first photo seems to be for a cartridge filter. Is that your "pre-filter? Is that a 4.5x10 filter, or what?

What is your "carbon filter" -- another cartridge filter, or a backwashing filter that looks like another softener? Would the backwashing carbon filter be before the softener, or would the carbon block cartridge filter be after the softener? Carbon block before the softener is a no-go.

Is your main question whether a single fitting with MNPT threads on one end and pex on the other be OK rather than 3 pieces? Yes. For that, I would use both PTFE tape and pipe dope for the threads. Using both makes a leak less likely. Don't tighten as hard as you can.

Still, you might want to describe your plan more completely, including PEX size, order of things, and whatever.

 

[Sponsor]

 

[Bannerman]

The diagram in your 2nd image, shows a manual backwash valve which would be a suitable choice for occasionally (monthly?) backwashing a large tank of granular activated carbon media. Those manual backwash valves are typically produced overseas and are often not equipped with NPT threaded female connections, but instead, utilize British Standard Pipe Thread (BSPT). BSPT is considered to be incompatable with the North America NPT standard as the BSPT utilize a 55° thread angle vs 60° for NPT. BSPT also utilize a rounded thread profile vs a sharp profile for NPT.

Although some proceed to utilize NPT fittings using sealants without issue for connecting to those valves, the additional threaded fittings could possibly be adaptors to convert BSPT to NPT to provide full compatability.

With regard to the manual backwash valve, those are not typically supplied with a drain flow control, so your will likely need to add a drain flow restrictor, to reduce the backwash flow rate to the appropriate flow rate for the specific media, tank diameter and water temperature. While it's possible to purchase an addon drain flow control including an appropriate flow rate drain restrictor button, another option will be to utilize a locally available ball valve which is to remain partially closed to reduce the flow rate to equal the appropriate flow rate to drain during the backwash and rapid rinse (media recompaction) cycles.

 

[IPDQKWID]

Your first photo seems to be for a cartridge filter. Is that your "pre-filter? Is that a 4.5x10 filter, or what?

What is your "carbon filter" -- another cartridge filter, or a backwashing filter that looks like another softener? Would the backwashing carbon filter be before the softener, or would the carbon block cartridge filter be after the softener? Carbon block before the softener is a no-go.

Is your main question whether a single fitting with MNPT threads on one end and pex on the other be OK rather than 3 pieces? Yes. For that, I would use both PTFE tape and pipe dope for the threads. Using both makes a leak less likely. Don't tighten as hard as you can.

Still, you might want to describe your plan more completely, including PEX size, order of things, and whatever.

Thanks, Reach. Yes, the pic shows the head for the pre-filter, 4.5"x19". The other photo from the booklet shows the head/handle for what I called the carbon filter, and yes, it looks just like the softener. It is specifically a KDF media tank, with backwashing capability. Thanks for the tip on the pipe dope, that was probably going to be my next question, tape or dope or tape+dope?

The house is plumbed off my city water meter directly to 3/4" by a 1x3/4 reducer coupling.

The softener control valve and the valves for the media tank and pre-filter all have 1" fittings. My plan is to increase pipe size to 1" by replacing the water meter coupler and threading on FNPT x PEX 1", then going up to the softener/filtration system with 1" pex: shut-off valve -> pre-filter -> KDF media tank -> shut-off valve -> softener -> reducer coupling back to 3/4" -> in-line pressure gauge -> tie back into piping to cold water supply and the water heater supply.

Bannerman - Thanks, I'm going to look more closely at the threads and backwash flow rates. I was a little surprised that I needed to supply a drain line for the backwash port. One follow-up question - is the flow rate out during backwash needing to be optimized so that media isn't lost as it expands?

 

[Bannerman]

. It is specifically a KDF media tank, with backwashing capability

KDF is drastically different than carbon. What size tank are you intending to use for this backwashing KDF media?

Either type of KDF media is extremely heavy media which will require 25-30 GPM per ft2 to backwash.

If planning a 9" diameter tank, the backwash requirement would be 11-13 GPM. For an 8" diameter tank, that would be 8.5 - 10 GPM. Even at those backwash rates, when using 60 F temperature water, the expansion factor will be only 10-15%.

The recommend service flow rate to faucets for KDF is 15 GPM per ft2, so 6.6 GPM for a 9" tank, or 5.1 GPM for an 8".

 

[IPDQKWID]

Thanks for the flow numbers, that makes sense once I remember my 2*pi*r geometry.

The riser tube inside both the softener tank and the KDF tank each extend about 1/4" above the top of the tank opening.
How big of a deal is this? The install instructions make note of ensuring the riser tube is flush. The riser tube seems immovable.
Thanks for any insight.

 

[Bannerman]

The install instructions make note of ensuring the riser tube is flush. The riser tube seems immovable.

I have no current expereince with either of those valves. There maybe no issues with the riser tube being slightly longer, or threading the valve to the tank could cause the riser tube to bend and crack or the bottom basket to become compressed, which could result in breakage over time. The riser height is to be checked and adjusted while the tank is empty, prior to adding bedding gravel and media.

What diameter is the KDF tank? How is the backwash drain rate to be controlled?

 

[IPDQKWID]

It is a 9" tank, and best I can find, a backwash flow rate is listed as 17gpm AquaTrol Valve Specs
I believe I have an AQT-MFV-1
Another product sheet lists the Water Capacity BackWash as 19 gpm
As far as controlling water flow to get to that point, does the valve restrict enough flow to get it down to 17 gpm?