3/4" NPT Male Union AutoFill Filling Valve Zoom

3/4" NPT Male Union AutoFill Filling Valve


Brand: Caleffi

Qty Price
/ each
$287.85 / box (3 units x $95.95)
In Stock! Ships in 24-48 Hours
(30 Available)



Size: 3/4"
Connection Type: Male NPT Union
Max Temp (F): 140°F
Max Pressure (PSI): 365
Pressure Set Point: 15 psi
Material: Brass

Description for Caleffi 535051A

The 5350 series AutoFill automatic filling valve is a pressure reducing valve which when installed on the water inlet piping in closed hydronic systems will maintain system pressure at a set value, automatically filling up with water as required. It fast fills the system to set pressure then automatically shuts off the water feed. This product is factory pre-set to 15 psi system pressure. To adjust the set pressure, simply turn the adjustment knob while observing the integral downstream pressure gauge. This product has the characteristic of being pre-adjustable, which means that it can be adjusted at the right pressure value before the system charging phase. After installation, the system pressure will automatically adjust itself to the set value and the water feed will stop when the set pressure is reached. The internal cartridge containing all the controlling components is pre-assembled as a self-contained unit, to facilitate inspection and maintenance procedures.

Technical specifications

  • Materials - Body: Brass
  • Cover: Glass Fiber Reinforced Nylon PA66G30
  • Control Spindle: Stainless Steel
  • Moving Parts: Brass
  • Diaphragm and Seals: NBR
  • Filter: Stainless Steel
  • Suitable fluids: Water
  • Max. Working Pressure: 365 psi (25 bar)
  • Downstream Pressure Setting Range: 6-90 psi (0.5-6 bar)
  • Factory Setting: 15 psi (1.035 bar)
  • Max. Working Yemperature: 140°F (0-60°C)
  • Pressure Gauge Scale: 0-100 psi (0-7 bar)
  • Filter Mesh Size: 0.51 mm (35 mesh)

3/4" NPT Male Union AutoFill Filling Valve


by PowerReviews
Caleffi3/4" NPT Male Union AutoFill Filling Valve

(based on 1 review)

Ratings Distribution

  • 5 Stars



  • 4 Stars



  • 3 Stars



  • 2 Stars



  • 1 Stars



Reviewed by 1 customer

Displaying review 1

Back to top


Good all purpose valve

By Fred the plumber

from Northeast

Verified Buyer

Comments about 3/4" NPT Male Union AutoFill Filling Valve:

Good working valve, adjusts easily,
Replace the gauge, leaked out of the box.
Installed a better gauge with lower pressure reading, installed on residential boiler, only 12 - 15 psi,

  • Was this a gift?:
  • No

Displaying review 1

Back to top

Q&A: Ask the Questions, share answers

Do you have questions about this product?

Get answers from real customers and in-house experts with AnswerBox.

1 Question | 1 Answer
Displaying question 1
  • 3/4" NPT Male Union AutoFill Filling Valve


    Will this work for a combi gas boiler which requires a lead free autofill valve? In other words, is this AutoFill Filling Valve lead free?
    Asked on 11/21/2014 by Nai

    1 answer



      no its not lead free

      Answered on 12/26/2014 by Supplyhouse Staff from New York
Displaying question 1

Do you have a question about this product?