Plast-O-Matic RVT Series User manual

INSTRUCTIONS
I. IMPORTANT – BEFORE INSTALLING
RVT-0219-I-1
SERIES “RVT” RELIEF VALVES
INSTALLATION AND MAINTENANCE INSTRUCTIONS
Series RVT relief valves will open when inlet pressure exceeds
the set pressure, when properly installed and used within the
recommended ranges of pressure, temperature, and chemical
compatibility. The ultimate determination of material
compatibility is previous successful use in the same application.
Call our Technical Support for information about your
application.
CAUTION: Series RVT is not a pop safety relief valve. It is not
intended for air or gas service. It does not regulate pressure
downstream of the valve. Connecting the outlet to a suction line
may cause air to be drawn into the line. Connecting the outlet to
a pressurized line or vessel may cause valve malfunction.
Plastic materials will degrade in ultraviolet (UV) light or sunlight.
Polypropylene and PVDF often look similar. Do not install in your
system if you are not sure.
II. INSTALLATION INSTRUCTIONS
Install the valve in the proper flow direction as indicated by the
flow label. The valve may be set vertically or horizontally.
A. THREADED CONNECTION
Apply a suitable thread sealant (for example, PTFE tape) to
male tapered threads to assure a “leak-tight” seal. Assemble
“hand-tight” followed by a quarter (1/4) turn with a strap
wrench. Do not over tighten or use pipe wrenches on plastic
pipe and components. CAUTION: PTFE tape will “string” as
pipe threads are joined. Loose “strings” could lie across the
seating surface and prevent the valve from completely closing.
To avoid this problem, clean out old tape, and do not apply
tape to the first thread.
CAUTION: Connect to plastic pipe and fittings only; when using
metal pipe, install an intervening plastic fitting. Metal pipe and
straight threaded pipe tends to cut, stretch, and distort the
plastic bodies, resulting in cracking or leaking over time.
NON-THREADED CONNECTIONS – For solvent cementing
or heat fusion, follow the instructions supplied with the cement
or fusion equipment, of contact your distributor.
MOUNTING: These valves are designed to be supported by
the piping. The piping must be properly supported, taking into
account the weight of the valve, piping, and process liquid.
BODY
MAT’L COLOR at 77ºF (25ºC) at 104ºF (40ºC) at MAX TEMP.
PVC DARK GRAY 150 PSI 10 Bar 106 PSI 7 Bar 34 PSI @ 140ºF 2 Bar @ 60ºC
CPVC LIGHT GRAY 150 PSI 10 Bar 120 PSI 8 Bar 37 PSI @ 180ºF 2 Bar @ 80ºC
Polypro TRANSLUC. WHITE 150 PSI 10 Bar 125 PSI 8 Bar 40 PSI @ 180ºF 2 Bar @ 80ºC
Kynar PVDF TRANSLUC. WHITE 150 PSI 10 Bar 120 PSI 8 Bar 22 PSI @ 280ºF 1 Bar @ 140ºC
PTFE OPAQUE WHITE 150 PSI 10 Bar 140 PSI 9 Bar 10 PSI @ 280ºF 69 Kpa @ 140ºC
MAXIMUM INLET PRESSURES for WATER*
*or compatible chemical – rating reduced for some applications. Not rated for suction or vacuum. Minimum
temperature 40°F (5°C). EPDM seals limited to 250°F (120°C), FKM to 300°F (148°C). See the Product Data Sheet
or consult our Technical Support staff for more information.

INSTRUCTIONS
SERIES “RVT” RELIEF VALVES
RVT-0219-I-2
III. OPERATION
RELIEF OPERATION
The function of a relief valve is to protect a pressurized
pipeline, vessel, or other similar system from excessive
pressure. When the inlet pressure exceeds the set point, the
valve opens to bleed off the excess pressure.
BACK PRESSURE OPERATION
A back pressure valve controls pressure in a line or system by
closing when the pressure drops below the set point. Pressure
at the outlet can drop, but upstream pressure is maintained.
BY-PASS OPERATION
A by-pass valve is set on the outlet of a pump (see figure) to
prevent dead-heading and control the pump’s outlet pressure.
When pressure exceeds the set point, the valve opens to allow
the liquid to recycle (by-pass) to the pump inlet.
IV. PRESSURE SETTING INSTRUCTIONS
Series RVT pressure relief valves sense inlet pressure;
therefore it may be helpful to install a pressure gauge at the
inlet of the valve for setting.
Setting for relief or backpressure operation:
1. Install the relief valve in the piping system.
2. Loosen the locking nut on the adjusting screw assembly
and turn the adjusting screw all the way in.
3. Increase the inlet pressure to the desired set point.
4. Turn the adjusting screw slowly out until flow is observed.
5. Tighten the locking nut to lock in the setting.
Relief valves may be set off-line using pressurized air. Connect
the inlet to a pressurized air supply that is regulated to the
desired set pressure. Fill the outlet port with water, or run a line
into a container of water, to observe bubbles.
V. MAINTENANCE
Plast-O-Matic recommends keeping a spare seal kit available
for repairs. Seal life will vary in applications due to cycles,
temperatures, pressures, chemicals, and concentration. Based
on the application, a periodic inspection and maintenance plan
should be established. The seal kit part number is “SK” plus
the part number less the material suffix. For example, the seal
kit for RVT050V-PV is SKRVT050V.
BYPASS
TO TANK
TO POINTS OF USE
PUMP
SUPPLY
Typical By-pass Operation

RVT-0219-I-3
SERIES “RVT” RELIEF VALVES
• Before disassembly, relieve pressure and drain fluid from
the valve and piping to be opened. Take proper
precautions to protect people and equipment from any
residual liquid.
• Disassemble the valve in a clean environment. Prevent any
dirt, grit, or fiber from getting onto the sealing surfaces or
into the moving parts. Do not scratch or damage plastic
parts.
• A non-scratching probe such as an orangewood stick or
ball end dental pick (burnisher) should be used to remove
and install O-rings, U-cups and seat gaskets.
• Pipe wrenches and vises are not recommended for plastic
valves. Strap wrenches can be used in most cases.
• Refer to the valve instruction sheet for installation to piping.
DISASSEMBLY
1. Back off the adjusting screw to release pressure.
2. Remove the four screws and the flange ring.
3. Disassemble as shown in figures 3, 2, and 1. Tweezers may
be needed to remove the U-cup inside the spring housing.
4. Remove and discard the seal kit items.
ASSEMBLY
1. When allowed, lubricate each item in the seal kit lightly with
an appropriate lubricant.
2. (for RVT050, skip to step 4) Bend one U-cup into a heart
shape and push into the groove inside the spring housing.
Use a probe or your finger to hold one lobe in the groove
and push the rest of the U-cup in.
3. Assemble the seat retainer assembly as shown in figure 1.
Hold the shaft with a rubber sheet
or glove, and screw on until tight.
Do not overtighten or use any
material which may scratch the
teflon shaft.
4. Assemble the rest of the parts as
shown in figures 2 and 3.
5. Replace the four screws, and nuts
if supplied. Torque 5 to10 inch
pounds.
NEED HELP?
Call 1-973-256-3000, fax to 1-973-256-4745,
or e-mail to [email protected],
for Tech Support.
(Have valve model number ready)
HEART SHAPE
REFER TO ILLUSTRATIONS ON PAGE 4.
INSTRUCTIONS
MODEL PIPE ADJUST SPRINGS
SIZE RANGE
RVT050 1/2˝ 5 - 25 LC042G-7
26 - 70 LC045G-7
71 - 100 LC055G-7
101 - 125 LC038E-14
RVT075 3/4˝ 5 - 30 LC055H-10
31 - 70 LC063H-10
71 - 100 LC072H
101 - 125 LC080H-9
RVT100 1˝ 5 - 25 LC072H-9
26 - 55 LC080H-9
56 - 100 LC080H-9 & LC091K-1
101 - 125 LC098H-9
RVT125 1 1/4˝ 5 - 15 LC063H-10
16 - 50 LC105L-8
51 - 70 LC120L-7
71 - 125 LHC156M-6
RVT150 1 1/2˝ 5 - 25 LC105L-8
26 - 59 LC120L-7
60 - 100 LHC148J-7
101 - 125 LLC105J-12 & LC135M-7
RVT200 2˝ 5 - 40 LHC162N-8
41 - 100 LHC218T-4
101 - 125
LHC162N-8 & LHC218T-4
SPRING REPLACEMENT
SEAL KIT REPLACEMENT

SERIES “RVT” RELIEF VALVES
INSTALLATION AND MAINTENANCE INSTRUCTIONS
INSTRUCTIONS
RVT050 SEAL KIT
Item Qty. Description
11SEAT GASKET
21or 2 SEAT RETAINER O-RING
33U-CUP SEAL
41SPREADER SEAL*
51BODY O-RING
* The “spreader seal” is the o-ring that is
nicked or cut to permit expansion.
RVT075, RVT100, RVT125, RVT150, RVT200 SEAL KIT
RVT-0219-I-4
*NOTE: 1" RVT uses two spreader seals.