PA VB 450-200 User manual

Latest Update: 20/04/2018
1
VB 450-200/300 -Unloader Valve
TechnicalBooklet:E258
Pressure regulating unloader valve.
It bypasses water flow at low pressure when gun shuts off.
DN 32
Technical Data
Max. Flow Rate: 450 l/min. Max. Temperature: 90°C (1)
P/N
RATED
PRESSURE
bar - MPa
PERMISSIBLE
PRESSURE
bar - MPa
MIN.
ADJUSTABLE
PRESSURE
bar - MPa
(2)MAX PRESS.
INCREASE AT
SYSTEM SHUT
OFF
%
(3)PRESSURE
DROP AT
BYPASS
RESET
%
INLET
OUTLET
BYPASS
WEIGHT
g
60.4020.00
200 - 20
220 - 22
20 - 2
10,7%
43,8%
1“1/4 Bsp FF
1“1/2 Bsp F
5950
60.4030.00
300 - 30
330 - 33
30 - 3
7,8%
43,3%
1“1/4 Bsp FF
1“1/2 Bsp F
6025
(1) The valve is especially designed for a constant use at a water temperature of 60°C. It can withstand up to a max.
temperature of 90°C for short intervals only.
(2) The max. pressure increase at system shut off is a percent value of calibration pressure. When it occurs, the valve is
set in operation and the whole fluid is diverted into bybass.
(3) The pressure decrease at bypass reset is a percent value of calibration pressure. It indicates the pressure drop
required for the valve to restore pressure in the system.
Instruction, Maintenance, Installation, Spare Parts Booklet.
For a correct use of the item, please follow the instructions.
Please copy all relevant information on the use and maintenance booklet of
the machine.
n. 12.9258.00
60.4020.00 VB 450/200 1”1/4 Bsp FF
60.4030.00 VB 450/300 1”1/4 Bsp FF
-Intended for use with high flow rates
-Special steel spring with superior mechanical features, to maintain
calibration settings for longer
-Check valve specifically designed to prevent jammings
-Screw/Locknut adjusment to set maximum pressure level
-Dynamic seals with O-ring and sliding gasket
-Fixing screw slots

Latest Update: 20/04/2018
2
DIMENSIONAL DRAWING
INSTRUCTIONS
SELECTION
This product is to be used with clean, fresh water, or water slightly additivated with ordinary detergents. For use involving harsh or even
corrosive fluids, always ask PA Technical department first. Appropriate filtration should be installed when using unclean fluids.
To select the right valve, always take in consideration rated running data of the system (rated pressure, max. flow rate and max.
temperature). In no case shall the system pressure exceed the permissible pressure marked on the valve.
INSTALLATION
On a water heating machine, fit the valve before the heat generator. This product is bound to be incorporated on a finished machine.
On a water heater, it is necessary to mount accessories that limit the accidental increase of fluid temperature.
Always install a safety valve to protect the pressurized outlet channel.
Select the right nozzle size, which allows a regular discharge into bypass of at least 5% of the total flow rate of the system. This will
keep a constant pressure setting and prevent pressure spikes at shut off which could damage the system.
By nozzle wearout, the pressure drops. When replacing the nozzle, reset the system to the original pressure level.
OPERATION
The valve regulates the max. system pressure through a piston, which acts on a cone that, normally positioned, closes the bypass
opening. A check valve cuts out the delivery section, the pressure of which controls the piston drive.
All adjustments should be carried out when the system is in operation and the nozzle is working.
IMPORTANT: The nut (pos.15) must never be removed, as it is a mechanical safety device that limits the max pressure and
prevents serious damage to persons and things.
DISCHARGE SYSTEM AND WATER ADDUCTION
The bypass conduct shall discharge outside of the machine or into a tank, but never directly into intake conduct. In case, it is advisable
to install a baffled tank.

Latest Update: 20/04/2018
3
PROBLEM HANDLING: CAUSES AND SOLUTIONS
PROBLEMS
PROBABLE CAUSES
SOLUTIONS
Valve recycles frequently
Check Valve O-ring worn out
Leaking couplings
Bypass blocked or throttled
Replace
Check and Restore
Clean or Adjust
Valve does not reach
desired pressure level
Piston seals worn out
Material matter between seat and shutter
Nozzle worn out
Replace
Clean up seat
Replace
Pressure spikes
Less than 5% of total flow rate discharged in bypass
Excessive flow rate in bypass
Adjustment carried out with spring completely
compressed
Reset
Choose different valve type or adjust passages
Loosen knob and replace nozzle
Valve does not bypass at
low pressure
Jammed check valve
Check valve O-ring worn out
Material matter on check valve
Clean or replace
Replace
Clean
REGULATIONS : See Standard Manual.
referred to in the Declaration of Conformity.
For a correct use, follow the instructions given in this booklet and re-print them on the Use and
Maintenace Manual of the machine.
Make sure that you are given the original Declaration of Conformity for the chosen item. This booklet is
applicable for all unloader valves type VB 450-200/300
MAINTENANCE
All maintenace operations must be carried out by qualified personnel only.
ROUTINE: every 400 hours of operation (around 10000 cycles), check and lubrify seals with waterproof grease.
EXTRAORDINARY:every 800 hours of operation (around 20000 cycles), check conditions of seals and other internal
components. If required, replace them with original PA spare parts.When installing the spares, lubrify them with
waterproof grease.
IMPORTANT: in case of replacement, assemble the valve correctly, resetting all conditions to starting levels
and making sure to fix the nut pos.25 with thread locking liquid.
The manufacturer is not liable for damages resulted from incorrect fitting and maintenance.
Technical data, descriptions and illustrations are indicative and subject to modification without notice.

Last updated 24/10/2020
60.4020.00 VB450/200 unload. 1"1/4 Bsp F
60.4030.00 VB450/300 unload. 1"1/4 Bsp F 60.4220.00 VRP 450/200 reg.valv 1"1/4 Bsp F 60.4230.00 VRP 450/300 reg.valv.1"1/4 Bsp F
Pos. P/N Description Q.ty K1K2K3K4 Pos. P/N Description Q.ty K1K2K3K4
1 60.4014.31R Piston holder, 1"1/4 Bsp F 1 3
2 10.3208.28R O-ring, 2,62x36,17 mm Ni85 2 • • 5
3 60.4013.51R Spring, 1,6x23,1x44mm (1,2) 1 3
4 60.4012.31R Check valve (1,2) 1 3
5 10.3350.00R O-ring, 6x18 mm (1,2) 1 • 10
6 60.4001.35R Housing -VB450, 1"1/4Bsp F, brass 1 1
7 10.3077.08R O-ring, 1,78x28,3 mm Ni 85 1 • • 10
8 60.4002.51R Seat 1 • • 3
9 60.4003.51R Shutter, M 12 1 • • 3
10 10.3206.08R O-ring, 2,62x28,25 mm Ni85 1 • • 10
11 60.4005.31R Bushing 1 3
12 10.4084.00R Back-up ring, 16x20,5x2mm 1 • • 5
13 10.3181.20R O-ring, 2,62x15,88 mm 1 • • 10
14 60.4007.31R Bushing 1 3
15 10.3246.05R O-ring 3,53x28,17 mm 1 • • 5
16 10.4096.00R Back-up ring, 28x34x2mm 1 • • 5
17 60.4004.51R Piston, M 12 1 3
18 14.7465.00R Ball, 1/2" Sst. 1 5
19 60.4009.31R Piston holder 1 1
20 60.4010.31R Ball holder 1 3
21 60.4006.61R Spring, 9x33x110mm 1 2
22 60.4015.61R Spring (2,3) 1 2
23 60.4016.31R Spring holder 1 3
24 60.4008.31R Screw plug M 48 1 3
25 11.4845.00R Nut, M16x1,5 Sst. 1 5
26 60.4011.51R Screw, M16x54mm Sst. 1 3
Kit P/N Description
K1 60.4022.24 Spares kit -VB 450/200-300, 10x1pcs. 1
K2 60.4222.24 Spares kit -VRP 450/200-300, 9x1pcs. 1
(1) 60.4020.00 (2) 60.4030.00 (3) 60.4230.00