Synesso MVP, Technical Manual

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The following instructions are intended to ensure the proper function of the pressure relief valve (PRV). We
suggest the procedure be performed as a part of the twice yearly periodic maintenance schedule.
1. Cool and depressurize the steam tank.
2. Remove the yellow tubing guard surrounding the PRV.
3. Check that the sealing face and rod move freely by pulling the test ring. There will be spring resistance,
but the seal should open easily and travel smoothly. If the seal sticks or the spring feels gritty, the valve is
scaled and should be replaced.
4. Replace the yellow tubing guard.
5. Disconnect the green fill probe wire from the upper level probe (located on the left side of the steam
tank).
6. Allow steam tank to over - fill. Watch the steam tank pressure gauge. Once the water closes the vacuum
breaker, the PRV should release water. Note the pressure displayed on the steam tank gauge when this
occurs. The pressure at the point of release should be 50psi.
7. Replace the green fill probe wire. Drain the steam tank until the fill valve activates.
8. Reheat the steam tank.
9. Remove the yellow tube guard and check the PRV for leaks. Listen for hissing. Replace the PRV if it will
not seal.
10. Replace yellow tube guard.
An older gauge is potentially less reliable than when first manufactured. Additionally, a steam tank gauge
that has exceeded its scale limit of 60psi may be damaged internally. If after experiencing high pressure, the
gauge cannot return to the zero point, it has been damaged and should be replaced.
Gauge readings are less accurate the further they are from the center point of the readable scale. When
measuring readings near 50psi on a 60psi max gauge, the results may be as much as 10% off in either direc-
tion. With that in mind, PRVs releasing at a gauge pressure anywhere between 45 and 55psi are acceptable.
The body of the PRV is mostly hollow, so open end wrenches and other pliers can cause the PRV to collapse
or distort during removal or installation.
Use only closed end wrenches on PRVs. Seal with red Loctite.
Assembled steam tanks are pressure tested up to 75psi at the factory before the PRV is installed.
PRESSURE RELIEF VALVE MAINTENANCE PROCEDURES