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Home/Pumps and fluid handling/Caleffi hydronic components/521518A

Caleffi · 2026 catalog

521518A

¾" PEX expansion union 3.0

Weight2.5 lbFirst PDF occurrence55Official source ↗

Published catalog evidence

Exact manufacturer record

January 2026
Code
521518A
Description
¾" PEX expansion union 3.0
Catalog weight
2.5 lb
Published row
521518A ¾" PEX expansion union 3.0 2.5 -

Verification boundary

What still needs to match

Do not infer interchange
Function and seriesConfirm valve, separator, manifold, fill, control, backflow, or accessory function and exact series.
ConnectionsVerify NPT, sweat, press, PEX, flange or union connection type and size.
Hydronic dutyCheck pressure, temperature, flow/Cv, materials, seals, potable/hydronic approvals, and control compatibility.
InstallationConfirm orientation, envelope, service access, and current Caleffi documentation.

Related catalog codes

Same code prefix

8
2.4 lb521406A½" press union 3.02.5 lb521406AC½" press union, check valves 3.02.4 lb521506A¾" press union 3.02.5 lb521506AC¾" press union, check valves 3.02.6 lb521606A1" press union 3.03.1 lb521606AC1" press union, check valves 3.02.4 lb521409A½" sweat union 3.02.4 lb521409AC½" sweat union, check valves 3.0