CSA VSM User manual

CSA treated water line
Direct acting upstream pressure
relief-sustaining valve
Mod. VSM

Direct acting PSV Mod. VSM
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Personnel involved in the installation or maintenance of valves should always be alert
to potential emission of water and pipeline material, and take the necessary safety
precautions. Always wear the suitable protection like helmets, gloves, googles, when
dealing and handling hazardous pipelines and valves.
Introduction
This manual will provide you with the information to properly install and maintain CSA direct acting
pressure relief/sustaining valves Mod. VSM. The contents and the procedure are intended for
technicians in charge of CSA valves only, prior to a theoretical and practical training by CSA
qualified or authorized personnel.
Safety
All safety messages in the instruction manual are flagged with the following symbol meaning
danger, caution and warning. This means and makes reference to procedures that may lead to
equipment and system damage and to severe injury or death for the personnel involved.
Inspection
Your valve VSM has been packaged to provide protection during shipment, however it can be
damaged during transport. Please carefully inspect the unit for damages or discrepancies with the
order upon arrival and report a claim immediately before unloading the goods.
Parts
Recommended spare parts are listed on the assembly drawing depicted on page 8.These parts
should be stocked to minimize delays in case of malfunction. When ordering spare parts please
make reference to the assembly drawing and identification plate present on the valve.

Direct acting PSV Mod. VSM
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Contents
Description - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 4
Handling and storage - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 4
Fusion/Powder coated valves- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 4
Installation - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 5
Maintenance - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -6
Set up - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 6
Drawings- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -7
Troubleshooting- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -8
Disassembly- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 10

Direct acting PSV Mod. VSM
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Valves with fusion/powder coated exterior paint require flat washers to be installed
under the flange nuts when installing the valve to the pipeline flange, to prevent the
paint from cracking or chipping.
Personnel involved in the installation or maintenance of valves should be constantly
alert to possible damages caused by an improper handling of the valve.
Description
The automatic direct acting PSV Mod. VSM consists of a upstream pressure balanced single seat
globe pattern valve, piston actuated, and equipped with a spring located in the cover to impart the
force necessary for the proper working. The operating principle is explained in detail on the
technical catalogue, for further explanations please contact us. The VSM will automatically throttle
and modulate the water supply to maintain a preset and adjustable upstream pressure, regardless
of upstream pressure fluctuations, . The special design of CSA with built in self cleaning piston
technology guarantees long lasting performances with a dramatic reduction of the maintenance
time, minimizing the risk of friction and malfunctioning.
Handling and Storage
Lifting the valve improperly may damage it. Lift the valve with slings, chains or cables fastened
around the valve body or eyebolts if present, or fastened to bolts or rods through bolt holes in the
flanges. Do never lift the valve by the adjusting screw. If installation will be delayed, place valve
indoors in secure, weather tight storage. If temporary outside storage is unavoidable, make sure a
vermin proof rain cover is secured around/over the valve to keep off rain and mud. Skid and set the
assembly on a flat, solid, and well drained surface for protection from ground moisture, runoff and
pooled rain water. Do not leave the valve exposed to high humidity and excessive temperature
conditions.
Fusion/Powder Coated Valves

Direct acting PSV Mod. VSM
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The difference in pressure generated by the valve when closed or during modulation
will produce a thrust proportional to the pressure itself.
Anchorage blocks and way of preventing valve’s movement or shifting need to be
taken into account.
Installation
The pressure relief/sustaining valve should always be installed in a horizontal position, meaning
the axis of the valve versus the ground level. Vertical installation is allowed up to the DN 100 mm
prior to consult with us. The valve has to be installed between two sectioning devices, one
upstream and one downstream to allow for maintenance, with a filter upstream of it to prevent dirt
from creating malfunctioning. For the recommended flow rate and differential pressure please refer
to the sizing information displayed in the catalogue or contact us, sending the project, data for
further assistance and valve sizing.
Before installation, remove foreign material such as weld spatter, oil, grease, and dirt from
the pipeline.
Prepare pipe ends and install valves in accordance with the pipe manufacture’s instructions
for the joint used.
Tighten the flange bolts or studs in a crisscross pattern and minimum of four stages.
Place the valve in the right direction following the arrow moulded on the body
If not included in the order install a pressure gauge upstream to check both the value in
dynamic conditions and the maximum static pressure. reached during closing. and make
sure it doesn’t exceed the valve’s design pressure
Note to Engineer: The direct acting pressure relief/sustaining valve VSM will regulate and
maintain an upstream pressure value according to the force of the spring, located inside the
cover, supplied with two different range (standard version):
Upstream pressure regulation from 1.5 to 6 bar (blue spring, standard)
Upstream pressure regulation from 5 to 12 bar (red spring, standard)
The spring range is indicated on the stainless steel identification plate and on the order
confirmation, should the pressure needed be different or outside of the range please
contact us for an immediate replacement of the spring, do not exert excessive torque on the
spring or relief it completely

Direct acting PSV Mod. VSM
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When the valve reacts to modulate, in sustaining the upstream, pressure, the effective pressure
variation on the line depends on the length of the entire system and part of the network subject to the
VSM. This could take sometimes minutes, therefore allow for it before acting on the spring.
The flow rate is an effect of the pressure controlled by the VSM for that specific system. An inlet
pressure value, maintained for an instance at 3 bar, wouldn’t produce the same flow rate everywhere
as it depends on the headloss between the valve itself and the final boundary conditions.
Maintenance
The pressure relief/sustaining valve VSM is sturdy and reliable, and it was designed to minimize
maintenance. A semi-annual visual inspection for the proper movement of the piston and the
cleaning of the compensation chamber is recommended. A routine maintenance for gasket,
control, o-rings and if needed replacements is recommended every 4 years and explained on page
10 ref picture 1 on page 7. A possible malfunction can be identified by a leakage through the seat,
normally caused by dirt accumulated inside the body, or seeping through the shaft and leaking
through to the cover, hunting and excessive variation of the upstream pressure.
Set up
Before the start-up of the valve make sure the instructions provided on the maintenance
section “Installation” on page 5 were properly followed and understood.
Operate very slowly on the following procedure to avoid stresses on the valve and
unexpected pressure surges.
The valve is initially isolated from the main line by means of the sectioning devices
upstream and downstream.
Open the downstream gate valve by 30%, then open slowly the upstream sectioning device
to generate some flow through the valve. Make sure the maximum nominal pressure is not
exceeded during this operation.
Unless the valve has been ordered with a specific setting turn the adjusting screw (9)
anticlockwise to relief the spring (not completely), make sure VSM will respond with a
smooth modulation by reducing the upstream pressure increasing the flow.
Open completely the downstream gate valve.
Let VSM work and modulate according to the demand, act on the adjusting screw (9) by
turning it clockwise to increase the upstream pressure, anticlockwise to decrease and
check the pressure gauges for further reference.
Allow for enough time for the system to balance.
By means a pressure gauge upstream and a flow meter make sure that both the flow rate
and difference in pressure, in dynamic condition, don’t exceed the recommended values
displayed in the catalogue.
Be sure to allow for at least 5 mt increase in the set pressure occurring between dynamic

Direct acting PSV Mod. VSM
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and static (no flow) conditions
Drawings
Picture 1
Recommended Spare parts nr: 13-21-22-23-24-25-26-27-28-30-32
9
8
7
4
14
5
21
10
11
25
20
28
23
29
15 24
1
19
12
22
27
18
30
17
16
13
3
6
2
26
31
32

Direct acting PSV Mod. VSM
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Problems solving
Condition
Possible Cause
Corrective Action
Valve leaks at flange joint.
Loose flange bolting.
Tighten flange bolting.
Blown flange gasket.
Replace flange gasket.
Miss-alignment or damage
to field piping and supports.
Adjust miss-alignment or
repair piping or supports.
Damaged flange face/s or
improper flange
connections.
Repair flange, replace
valve body or adjust flange
connections.

Direct acting PSV Mod. VSM
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Problems solving
Problem
Cause
Solution
The valve
doesn’t close
There is dirt accumulated between
the obturator and the seat
Remove the valve and clean it inside to
remove dirt
The pressure upstream is above
the set point
Check the pressure and adjust the
screw acting on the spring turning it
clock wise
There is dirt inside causing friction
to the piston
Check the movement of the piston and
remove dirt or foreign materials
The plane gasket of the obturator/
seat and / body is damaged due
cavitation and the valve can’t
assure a watertight sealing any
more
Check the difference in pressure,
operating cycles of the valve, flow rate.
Make sure they don’t exceed the advised
values from us technical literature
The valve
doesn’t open
The pressure upstream is below
the set point
Check the pressure and adjust the
screw acting on the spring by turning it
anti clockwise
There is dirt accumulated between
the obturator and the body
Remove the valve and clean it inside to
remove dirt
There is dirt causing friction to the
piston during its movement
Check the movement of the piston and
remove dirt or foreign materials

Direct acting PSV Mod. VSM
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Do not remove the nuts (17) holding the cover without having completely relieved the spring by
turning the screw (9) anticlockwise. Failing in doing so may cause severe damages and injuries
to the personnel .
Disassembly (toproceedwith itisnecessarytohave therequiredsparekeysandtools)
In order to carry out the proper maintenance of VRCD proceed as follows, ref drawing picture 1 on
page 7, for further info consult us :
1. slowly close the upstream and downstream gate valves;
2. if the VSM is installed in a location not suitable for maintenance, please remove it from
the pipe ;
3. turn the screw (9) anticlockwise to relief the spring (4)
4. remove the nuts holding the cover (17) and take out the cover (2) and spring (4)
5. be sure not to loose the spring guide (7) when the spring is removed
6. remove the driving tap (15) the hexagonal part of the main shaft (11) will be visible
7. push the mobile block from the shaft (11) downwards
8. set the hexagonal part with a wrench and keep it steady while unscrewing the first nut
(6) holding the piston tight
9. unscrew the upper ring (5) pulling it out along with the upper and lower piston (3 and
14) which do not have to be separated
10. Push the piston out of the ring paying attention not to damage the lip gasket (21), o-ring
(26) and the guiding PTFE ring (13)
11. Check the surface of the piston, clean it if necessary
12. Unscrew the lower ring (18) paying attention not to damage the o-ring (27)
13. Extract from above the spacer (12) and the o-ring (25)
14. Pull out the obturator block (20-28-29) paying attention not to damage the o-ring (32)
15. Check the surface of the plane gasket (28), replace if it necessary
16. check the downstream side of the reducer for possible sign of cavitation, holes
1) Reassembly
In order to carry out the proper reassembly of VRCD follow the instruction explained above on
page in reverse. Pay attention to:
1) use a proper grease on the piston, lip gaskets to allow for the proper movement of the
mobile block.
2) Once the valve has been fully assembled, prior to place the cover, check for the proper
movement of the mobile block making sure there are not sign of friction or any other
element affecting it.

Direct acting PSV Mod. VSM
11
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We reserve the right to incorporate our latest design and material changes without notice or obligation.
Design features, materials of construction and dimensional data, as described in this manual, are provided for your information only.