Function
The differential pressure by-pass valve is used in systems with a
fixed speed circulating pump supplying several zones controlled
by two way zone valves. This valve ensures that the head pressure
of the pump is proportional to the number of two way valves being
closed. It will bypass the differential pressure created by the pump
as the zone valves close, thus eliminating water hammer noise.
Product range
Code 519502A By-pass with flow up to 9 gpm. Size 3/4" MNPT
union inlet x 3/4" MNPT union outlet
Code 519599A By-pass with flow up to 9 gpm. Size 3/4" Sweat
union inlet x 3/4" Sweat union outlet
Code 519600A By-pass with flow up to 40 gpm Size 1" FNPT
inlet x 1" MNPT union outlet
Code 519609A By-pass with flow up to 40 gpm Size 1” Female
NPT x 1” sweat outlet
Code 519700A By-pass with flow up to 45 gpm Size 1 1/4" FNPT
inlet x 1 1/4" MNPT union outlet
Code 519709A By-pass with flow up to 45 gpm Size 1 1/4" FNPT
inlet x 1 1/4" Sweat union outlet
Technical characteristics
Materials
Body:
brass
Valve plug:
brass
Valve plug gasket:
peroxide-cured EPDM
O-Ring seals:
peroxide-cured EPDM
Union seals:
asbestos free NBR
Control knob:
ABS
Spring:
stainless steel
Performance
Suitable fluids:
water, glycol solutions
Max percentage of glycol:
30%
Temperature range:
32–230°F (0–110°C)
Maximum working pressure:
150 psi (10 bar)
Flow rates:
3/4” flow up to 9 gpm
1” flow up to 40 gpm
1 1/4” flow up to 45 gpm
Setting range:
1 - 6 m w.g. (2 - 10 psi)
CALEFFI
Adjustable differential pressure by-pass valve with graduated scale
519 Series
38482.0
5
www.caleffi.com
© Copyright 2018 Caleffi
SAFETY INSTRUCTION
This safety alert symbol will be used in this manual to draw attention to safety related
instructions. When used, the safety alert symbol means
ATTENTION! BECOME ALERT!
YOUR SAFETY IS INVOLVED! FAILURE TO FOLLOW THESE INSTRUCTIONS MAY
RESULT IN A SAFETY HAZARD.
These items are designed for use in closed hydronic systems. Do not use in plumbing
applications. These items do not meet the low-lead plumbing standards of U.S. and
Canada.
Code 519566A By-pass with flow up to 9 gpm. Size 3/4" press
union inlet x 3/4" press union outlet
