A.Y. McDonald 5121--14 503 Ser...
IN STOCK (leaves warehouse same day if ordered before 3pm ET)
$54.29
A.Y. McDonald 5121--14 503 Series Flare x FIP Adapter, 1-1/4"

A.Y. McDonald 5121--14 503 Series Flare x FIP Adapter, 1-1/4"

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Model: 5121-143

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

$54.29
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A.Y. McDonald 5121--14 503 Series Flare x FIP Adapter, 1-1/4"

The A.Y. McDonald 5121--14 is a 1-1/4" 503 Series Flare x FIP Adapter designed to transition flare tubing connections to female iron pipe (FIP) threaded connections. This fitting is a staple in water service and distribution installations where a reliable, leak-resistant connection is required between flare-end tubing and threaded pipe or fittings. Built to A.Y. McDonald's long-standing 503 Series design, this adapter is engineered for straightforward installation and dependable long-term performance in potable water and utility piping systems. The 1-1/4" trade size makes it suitable for a range of service line and distribution applications where this connection size is specified.

Key Features

  • Trade Size: 1-1/4" for water service line and distribution piping applications.
  • Connection Type: Flare x FIP configuration allows a secure transition from flared tubing to female iron pipe threaded connections.
  • 503 Series Design: Part of A.Y. McDonald's established 503 Series flare fitting line, recognized for consistent fit and function.
  • Adapter Configuration: Purpose-built to join dissimilar connection types without requiring additional couplings.
  • Installation-Ready: Designed for use with standard flare tools and threading practices common to water utility and plumbing trades.
  • Reliable Sealing: The flare-to-thread transition is engineered to minimize leak points at the connection interface, an important consideration for buried or concealed service lines.

Technical Specifications

  • Trade Size: 1-1/4"
  • Connection: Flare x FIP
  • Series: 503
  • Product Type: General Fitting / Adapter

Typical Applications

  • Water Service Line Connections
  • Distribution Piping Transitions
  • Utility and Municipal Water Installations
  • Flare-to-Thread Connection Points
  • New Construction and Repair/Replacement Work

Why A.Y. McDonald?

A.Y. McDonald has long supplied the water works and plumbing industries with fittings engineered for dependable, code-compliant performance. The 503 Series flare-to-FIP adapter reflects that same focus on straightforward, reliable connections between tubing and threaded pipe. Choosing an A.Y. McDonald fitting for this transition point helps ensure a consistent, professional-grade result on water service and distribution projects, backed by a manufacturer with a long track record in the water works industry.

Manufacturer Resources

Spec Sheet

Product Specs

Product Subgroup:
Fittings
Product Group:
Plumbing
Department:
Plumbing
Product Type:
General Fitting

A.Y. McDonald 5121-143 – Frequently Asked Questions

1) What connections does the A.Y. McDonald 503 flare x FIP adapter have?
One end is a flare connection and the other is FIP, female iron pipe thread. It lets you tie flare-type copper or poly tubing work into a male-threaded pipe or fitting without a separate coupling. A.Y. McDonald calls it the 503 flare x FIP adapter.
2) What sizes does the A.Y. McDonald 503 adapter come in?
Two sizes: 1 inch, part number 5121-143, and 1-1/4 inch, part number 5121-144. Both ends match the nominal size, so a 1-1/4 inch adapter is 1-1/4 flare to 1-1/4 FIP.
3) Will this A.Y. McDonald adapter work with a male threaded nipple or does it need a female outlet?
The FIP end is female, so it threads onto a male NPT nipple, male adapter, or male valve outlet. If the pipe you are connecting to is female threaded, you need a MIP (male thread) flare adapter instead, not this one.
4) Which A.Y. McDonald part number do I order for a 1-1/4 inch flare to FIP adapter?
5121-144 is the 1-1/4 inch 503 flare x FIP adapter. If your service line is 1 inch, order 5121-143 instead.
5) Do I need a flare nut and insert stiffener with the 503 flare adapter for poly tubing?
A flare connection on plastic service tubing is made up with a flare nut and an insert stiffener sized to the tubing; the adapter body itself is just the flared seat and the FIP thread. For copper tubing, the tube is flared and the flare nut pulls it against the seat. Order those tubing-side components separately in the same nominal size, 1 inch or 1-1/4 inch, to match the adapter.
6) Is the A.Y. McDonald 503 adapter used on water service lines?
Yes, it is a waterworks-type service fitting. The 503 flare x FIP adapter is the piece that joins a flared 1 inch or 1-1/4 inch service line to threaded pipe at a meter setter, curb stop, or yoke, which is where most municipal and irrigation service work uses it.
How fast can I get the A.Y. McDonald 5121-143 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 A.Y. McDonald 5121-143 come with a warranty?
Absolutely. The A.Y. McDonald 5121-143 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 A.Y. McDonald 5121-143?
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
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