Product Overview

Submittal Data # 101-070 Effective: 09/14/12
Supersedes: 07/15/05
Taco Inc., 1160 Cranston Street. Cranston, RI 02920 / [phone] / Fax [phone]
Taco (Canada) Ltd., 8450 Lawson Road, Unit #3, Milton, Ontario L9T 0J8 / [phone] / Fax [phone]
www.taco-hvac.com
Submittal Data Information
Cartridge Style Pressure Reducing Valve
Purpose
The 3350 valve is used to automati-
cally feed water to a hydronic system
whenever pressure in the system
drops below the pressure setting of
the valve.
Operation
The cartridge style design ensures
unsurpassed output pressure stabil-
ity. A balance between diaphragm
position and spring tension based
on the desired outlet pressure is
consistently maintained, even when
inlet pressures fluctuate severely. The
unique one-piece cartridge design
significantly reduces diaphragm load,
extending the overall product life.
Unlike conventional PRV designs, the
diaphragm does not double as a seal
between the body and the cap.
This allows for optimization of the
diaphragm for its intended use -
maintaining pressure stability.
A unique encapsulated shaft seal
system prevents flowing media
from contacting the diaphragm,
greatly extending diaphragm life. If
the diaphragm ever does fail, the
encapsulated shaft and body seals
work together to stop water from
exiting the valve. Use of a stainless
steel coaxial strainer prohibits system
debris from affecting the valves’
performance. An integral check valve
allows the cartridge to be removed
under system pressure for replace-
ment or servicing.
Fast Fill
The 3350 provides an efficient and
simple solution to filling your heating
system. Simply push down the fast
fill button on top of the PRV and
when the set pressure is reached the
valve pops out of fast fill and returns
to its normal operating mode. This
automatic reset feature of the fast fill
on the 3350 eliminates the common
problem of system over pressuriza-
tion and prevents the relief valve
from blowing off.
4-15/32”
(113mm)
1-1/2”
(38mm)
3-9/16”
(90mm)
4-1/4” Sweat Version (108mm)
(Includes Tailpiece)
Dimensions
for reference
purposes only.
1/2” — 14 NPT 1/2” — 14 NPT
1/4 — 14 UNS-2A
Features
Automatic Pressure
Reset from Fast Fill
Easy External Dial-up
Pressure Setting
Set Pressure Indicator
Simple serviceability with the
unique one piece cartridge
Internal check allows the
cartridge to be replaced
without draining the system
Integral Strainer
ASSE 1003
Product Specifications
Max. Inlet Pressure ..... 250 psi
Adjustment Range ...... 10 – 50 psi
Max. Temp. .................... 210°F
Factory Setting ............ 12 psi
Media ............................. Water
Materials of Construction
Body ................Forged Brass
Cartridge ........ Wetted Parts
.......................... Stainless Steel,
.......................... Engineered Plastics,
.......................... Bronze, EPDM Seals