Nibco 4551-W-3 Thread Flange F...
IN STOCK (leaves warehouse same day if ordered before 3pm ET)
$39.89
Nibco 4551-W-3 Thread Flange FPT - PVC Schedule 80, One-Piece Webbed Design

Nibco 4551-W-3 Thread Flange FPT - PVC Schedule 80, One-Piece Webbed Design

(No reviews yet) Write a Review

Model: CA25185

In Stock (leaves warehouse same day if ordered before 3pm ET)

$39.89
Adding to cart… The item has been added
Free Shipping on orders over $199
We price match and offer bulk discounts! Click Add to Quote. It's quick and easy.
✨
Earn points with this purchase! You can redeem points for giftcards, iPads, XBox's and more. View Rewards
Free Keying on all locks
You may also like
The dark grey PVC thread flange features a one-piece webbed design and a female pipe thread connection. Chemtrol® fittings connect PVC piping lengths together with solvent cementing, threading or flanging to create a highly reliable, leak-free system. Please refer to Chemtrol technical data sheets, chemical resistance guides and catalogs for engineering and installation information. PVC Schedule 80 has the highest long-term hydrostatic strength of any other major thermoplastic material used for piping. Chemtrol® PVC fittings are lightweight, easy to install, maintenance-free, and will not rust, scale, pit or corrode. Chemtrol® premium line of plastic fittings is backed by a 1-year limited warranty. Because Chemtrol® is a NIBCO brand the flow-control fittings are unsurpassed in quality, performance and longevity.

  • Maximum service temperature 140-DegreeF
  • Universal Part No. 852
  • One-piece webbed design
  • Female NPT thread connections and flange connections compatible with ANSI B16.5 Class 150
  • Do not use or test with compressed air or other gases
  • ASTM F1970
  • NSF/ANSI Standard 14
  • NSF/ANSI/CAN-61

Manufacturer Resources

Product Specs

All Application(s):
Lead-Free
All Basic Material:
PVC - Polyvinyl Chloride
Classification:
PVC Sch 80 Flanges
End Connection:
Threaded
Pipe Schedule:
80
Plastic End Connection Type:
F (NPT)
Product Group:
Fitting
Product Type:
PVC Sch 80 Flanges
System Use:
Commercial Plumbing, Industrial, Irrigation, Lead Free*
Product Subgroup:
Flange
Department:
Plumbing
Product Color:
Dark Grey
Country Of Origin:
United States

Nibco CA25185 – Frequently Asked Questions

1) What size pipe does the Nibco 4551-W-3 PVC Schedule 80 threaded flange come in?
The 4551-W-3 threaded flange is made in three pipe sizes: 2 inch, 3 inch and 4 inch. Each is a separate part, so order by size: 2 inch is CA25185, 3 inch is CA25195, 4 inch is CA25200. All three share the same one-piece webbed body and female NPT threaded socket.
2) Will a Nibco 4551 PVC flange bolt up to my cast iron or steel ANSI 150 flange?
Yes. The bolt circle on the 4551 series flange matches ANSI B16.5 Class 150 drilling, so it mates with any Class 150 flange of the same nominal size, metal or plastic. That is the whole point of using it as a transition at a pump, valve or tank nozzle. Bolt torque and gasket selection still follow the plastic side, not the metal side, since you are compressing a PVC face.
3) Does the Nibco 4551 flange glue on, or does it thread onto the pipe?
It threads. The hub is a female NPT socket, so it takes male-threaded Schedule 80 PVC pipe or a threaded nipple, no solvent cement involved. If your run is plain-end pipe and you want a cemented joint, you need the socket (slip) version of the flange instead, not this one.
4) What is the maximum temperature a PVC Schedule 80 threaded flange can handle?
140 degrees F is the ceiling for this Chemtrol PVC flange. Above that, PVC loses pressure capacity fast and the threaded joint is the first thing to relax. Hot water lines, boiler makeup, steam condensate and process lines that swing over 140 F need CPVC or metal, not this fitting.
5) Can I use a PVC flange on a compressed air line?
No. Chemtrol PVC fittings including the 4551 flange must not be used or tested with compressed air or other gases. PVC fails catastrophically under stored gas energy. Keep it to liquid service, and hydrostatically test with water only.
6) Is the Nibco 4551 PVC flange approved for potable water?
It carries NSF/ANSI Standard 14 and NSF/ANSI/CAN 61 listings and is a lead-free fitting, which is what a potable water spec asks for. It also meets ASTM F1970. Typical uses are commercial plumbing, industrial process, and irrigation.
7) What does a one-piece webbed flange mean, and is it stronger than a two-piece van stone flange?
One-piece webbed means the hub and the flange face are molded as a single part with reinforcing ribs (webs) running between them. There is no separate rotating ring, so the bolt holes are fixed relative to the hub. That makes it rigid and simple, but it means you have to rotate the pipe or the mating part to line the bolt holes up. A van stone style with a loose backing ring spins to align, which is the reason to pick one when the pipe cannot turn.
8) Do I need a gasket and bolts with the Nibco 4551 flange, or are they included?
The flange is sold as the fitting alone. Plan on a full-face gasket sized to the ANSI B16.5 Class 150 pattern for that nominal size, plus bolts, nuts and washers. Use flat washers under both the head and the nut so you are not digging into the PVC face, and pull the bolts up in a cross pattern to seat the gasket evenly. On the threaded hub side you will also need thread sealant rated for the service.
9) Will PVC Schedule 80 hold up in a chemical feed or process line?
PVC Schedule 80 has the highest long-term hydrostatic strength of the major thermoplastics used for piping, and it will not rust, scale, pit or corrode, which is why it shows up on industrial and chemical service. Whether it survives your specific fluid is a chemical-resistance question, and Chemtrol publishes resistance guides and technical data sheets for exactly that. Check your chemical against those before committing the run.
10) Can I use a PVC flange to make a serviceable disconnect at a pump or valve?
That is the main reason to specify one. Threading the 4551 onto the pipe and bolting it to the mating Class 150 flange gives you a joint you can break with a wrench, so a pump, strainer or valve can come out without cutting pipe. In a 2, 3 or 4 inch line that beats a solvent-cemented union for anything you expect to service. Keep the assembly supported so the flange is not carrying the equipment's weight.
11) Is the Chemtrol dark grey flange the same PVC as my white Schedule 40 fittings?
Different material grade and different pressure class. This fitting is dark grey Schedule 80 PVC; white fittings on a building are usually Schedule 40, which has thinner walls and a lower pressure rating. The threads will engage across the two, but joining Schedule 80 to Schedule 40 drops the whole joint to the weaker part's rating. On an industrial or irrigation main, keep the run in Schedule 80.
12) What is Universal Part No. 852 on the Nibco 4551 flange?
852 is the industry universal part number for a Schedule 80 PVC threaded flange, the cross-reference figure number used across manufacturers for this fitting style. If a submittal or a drawing calls out an 852 flange in FPT, the 4551-W-3 is that fitting. Nibco's own numbers for it are CA25185 in 2 inch, CA25195 in 3 inch and CA25200 in 4 inch.
How fast can I get the Nibco CA25185 delivered?
Most orders ship the same day from our distribution partners, with quick delivery throughout the continental U.S. Need it urgently? Contact Us for expedited shipping options.
Can I return it if it doesn’t work for me?
Yes—ZenSupply offers a hassle-free return policy. If the product isn’t the right fit, reach out to our support team for a return authorization or setup a return by following our return instructions.
Does the Nibco CA25185 come with a warranty?
Absolutely. The Nibco CA25185 is backed by a manufacturer’s warranty. For full warranty terms, check the product documentation or Contact Us.
How do I get technical support or installation help for the Nibco CA25185?
You can call, text, or email our expert support team for fast answers. We’re here to help with product selection, installation tips, and troubleshooting. Contact Us
Why buy the Nibco CA25185 from ZenSupply?
ZenSupply makes it easy to get the commercial door hardware you need—fast shipping, expert support, and rewards on every order. Our team is always ready to help you choose the right product for your project.
!