Clear Check Valve 2" - 1/2 lb. w/ Unions - 1700C20



Part # 1700C20

By Flo Control

  4.94 Average  



Part # 1700C20

Product Description

Flo Control check valve prevents backflow to protect sensitive equipment from chemical damage.

True union design allows the valve to be disassembled by unscrewing the in-line nuts, leaving the tail pieces cemented to the pipe. The valve body can be removed for visual inspection, repair, or cleaning, making it easy to change the body or spring tension.


  • Clear body
  • Size 2" IPS
  • Standard spring tension ½ lb.
  • EPDM seal and o-rings
  • 200 PSI static pressure rating @ 72ºF
  • Stainless steel spring
  • Excess solvent trap
  • Valve body length = 9.735" (body length includes unions)

Product Specifications

2 in.
1/2 lbs.

?     Asked on 10/30/2018 by Robert

Can this check valve be installed on a vertical position? Thanks

A     Answered on 10/30/2018 by InyoPools Product Specialist Hector F.

Yes, these valves can be installed that way as well. 

?     Asked on 7/31/2018 by JED


A     Answered on 8/1/2018 by InyoPools Product Specialist Lennox H.

Hi, Jed. The mechanism is unable to be replaced, however, it can be cleaned. 

?     Asked on 7/15/2018 by Jack Miles

I recently had a check valve fail and was unable to determine the type that was installed. Ended up purchasing a National Diversified swing valve. When removing the old to replace it I could see what I had purchased was different, and what was installed and failed was a Flo Spring check valve. Since the new one is not maintaining the spa level I want to replace it, is it normal for the swing valves to not work that well and are there different spring pressure I need to consider?

A     Answered on 7/16/2018 by InyoPools Product Specialist Lennox H.

Hi, Jack. There is a difference between a swing and spring check valve. Swing check valves is usually used in vertical plumbing appication and the spring can be used in either application. 

?     Asked on 6/16/2018 by Phillippp

I have a Pentair Clean and Clear Plus Cartridge Filter Purex Whisperflo WF28 Pump Triton MiniMax Plus Heater There is a 2" x 2lb check valve on the output side of the heater. The heater is old and broken. I am going to remove it from the system. Do I need a check valve if I remove the heater? If so what check valve do you recommend?

A     Answered on 6/22/2018 by InyoPools Product Specialist Lennox H.

Hi, Phillippp. A check valve is still needed between your chlorinator and filter. This 1/2 lb - 2" Clear Check Valve - 1700C20 will work. 

?     Asked on 9/30/2017 by steve mccain

I bought this valve before realizing I need a vertical valve with the water flow going down. 1hp Pentair pump, 2" PVC . Check valve between heater and chlorinator. Can you recomend one for me please

A     Answered on 10/3/2017 by InyoPools Product Specialist Lennox H.

Hi, Steve Mccain. If the water is flowing downward a check valve is not required. 

?     Asked on 4/4/2017 by

I have old Flo check valves that need to be replaced, model D-2466. Currently installed vertically with water flow moving downward. Will these check valves work?

A     Answered on 4/7/2017 by InyoPools Product Specialist Megan C.

Hello, this valve can be installed vertically but the manufacture states that it is recommended to be installed horizontally if at all possible.

?     Asked on 10/22/2016 by peter

I have a clear flo control check valve. The spring has no visible movement when I shut water off or on. Is this normal.

A     Answered on 10/24/2016 by InyoPools Product Specialist Lennox H.

Hi, Peter. The valve spring should open/close as water flows through the valve. The spring tension and the water flow will determine how fast the spring activates.

?     Asked on 6/20/2016 by Jesse

I have an in ground pool with a 1.5 HP pool (tower) pump. I need two new check valves. I am not sure how many pounds resistance needed for these valves. I see that valves with 1/2 lbs(like your 1700C20) along with 2 lbs and 5 lbs are sold. I'm not sure what I need exactly. One valve is between the heater and chlorinator, and one valve is on the drain from the spa. Will the 1/2 lb work for me?

A     Answered on 6/26/2016 by InyoPools Product Specialist Lennox H.

Hi Jesse, A 1/2 lb check valve is adequate for both application.

?     Asked on 5/31/2016 by Bobby Bouche

Is this check valve non-restricting, low restriction, or highly restricted?

A     Answered on 6/5/2016 by InyoPools Product Specialist Lennox H.

Hi Bobby, This valve has a 1/2 lb spring which is a low restriction valve.

?     Asked on 3/15/2016 by jerry s

We just purchased from you the Hayward 140,000 but Heat Pump. It calls for a 1/3 pound check valve to be cut in. I have one from you that is a 1/2 pound check valve. New. As I am not finding a 1/3pound anywhere, will the 1/2pound check valve work ok for this application. I have an inline chlorinator that this must go in between the heat pump and the chlorinator.

A     Answered on 3/17/2016 by InyoPools Product Specialist Lennox H.

Hi Jerry S, The 1/2 lb check valve would be okay to use.

?     Asked on 2/23/2016 by George

I am trying to find an exact replacement for an Inyo 1790C20 check valve so I can just switch out the body from the existing broken one. The PN on the valve is abraided but I think that is the number. This one seems close but the body is different and the OD with couplers is longer than mine which is 7 1/4". I don't have the space or pipe to switch to new couplers. Do you have an exact replacement? If not, what is the body length of just the check valve. Mine is 3 7/8".

A     Answered on 2/29/2016 by InyoPools Product Specialist Andy O.

Hello George, There is no exact replacement for the 1790C20.The per the manufacturer the body length on 1700C20 Clear Check Valve 2" - 1/2 lb. w/ Unions is 9.735".

?     Asked on 6/11/2015 by Darryl

I have no space for horizontal do they have a recommendation for a vertical mount

A     Answered on 6/11/2015 by InyoPools Product Specialist Patrick P.

Hi Darryl, this valve can be installed vertically.... horizontally is just the preferred method. You would want to make sure the flow of water is going up.

?     Asked on 6/9/2015 by Darryl Henry


A     Answered on 6/9/2015 by InyoPools Product Specialist Patrick P.

Hi Dave, this valve can be installed vertically but the manufacture states that it is recommended to be installed horizontally if at all possible.

?     Asked on 5/11/2015 by Timothy

I need to get the rubber seal ring and "O" rings - to replace - for the 2 inch check valve with the spring action gasket - the seal rings around the spring action valve has disintegrated - how do I find this

A     Answered on 6/12/2015 by InyoPools Product Specialist Lennox H.

Timothy, The rubber seal that goes inside of the Check Valve is not replaceable, would recommend replacing the complete check valve.

?     Asked on 5/6/2015 by Darryl Henry

Is this valve non corrosive? Can it be used safely with a salt water system?

A     Answered on 5/6/2015 by InyoPools Product Specialist Robert M.

Hello Darryl - This valve is chemical resistant and can be used in a salt water pool.

?     Asked on 2/14/2015 by

would this unit slide in place of the 2" pipe or would it need to buy adaptors to fit in place. The original check valve is the same length as yours but i don't know if the nuts would adapt to your check valve would appreciate your input. thanks.

A     Answered on 2/16/2015 by InyoPools Product Specialist Andy O.

This check valve will slip over 2" plumbing for installation. Without knowing which valve you currently have I can not say that the threading would be the same. But it more than likely would be a proprietary threading specific to the MFG.

?     Asked on 9/19/2014 by Guest

I would like to know the length of the body from end to end without the unions.I have a flo control valve in now and it is 5.25 inches from end to end without the unions.

A     Answered on 9/19/2014 by InyoPools Product Specialist Patrick P.

The length of the 1700C20 body without the unions is 6-1/8".

?     Asked on 1/4/2013 by Guest

What is the length of the fixed body without unions?

A     Answered on 1/4/2013 by InyoPools Product Specialist Patrick P.

The length of the 1700C20 Clear Check Valve 2" - 1/2 lb valve body without the unions is 6-1/8".

?     Asked on 1/18/2012 by Guest

Is it possible to purchase just the insert part of this as a replacement?

A     Answered on 1/18/2012 by InyoPools Product Specialist Patrick P.

There is no replacement part for that and you would need to replace the whole unit.


Est. Repair Time

Less than 1 hr

Tools Needed

hack saw

My old check valve was not closing properly.

Written on 9/4/2017 by Tim W.

I cut out the old valve using a hack saw. A union connection was then fitted and glued to place on the cut end of the 2 inch PVC pipe. The bottom of the new valve was cemented on this connector. .I loosen both ends of the new valve.The length of the valve was measured. Another union connector was fitted and placed on the remaining open end of the PVC. Since the new valve could be separated from the two connectors, it made the next step easy.The other end of the connector was primed and glued. I made sure the distance was right. The valve was placed and the connector ends were tightened. I waited 24 hours for the PVC glue to fully set. It works great. No leaks.

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