Adjustment of opening pressure:
① Before leaving the factory, the opening pressure of the safety
valve should be adjusted one by one to the setting value required
by the user. If the user proposes a spring working pressure level,
it should generally be adjusted and shipped according to the lower
limit value of the pressure level.
② Before installing the safety valve on the protected equipment or
before installation, the user must readjust it at the installation
site to ensure that the set pressure value of the safety valve
meets the requirements.
③ Within the range of the spring working pressure level indicated
on the nameplate, you can adjust the opening pressure by rotating
the adjustment screw to change the spring compression.
④ Before rotating the adjusting screw, reduce the valve inlet
pressure to less than 90% of the opening pressure to prevent the
valve flap from being rotated when the adjusting screw is rotated,
which may damage the sealing surface.
⑤ In order to ensure that the opening pressure value is accurate,
the media conditions, such as media type and temperature, should be
as close to the actual operating conditions as possible during
adjustment. The type of medium changes, especially when the medium
accumulation state is different (for example, from liquid phase to
gas phase), and the opening pressure often changes. When the
operating temperature increases, the opening pressure generally
decreases. Therefore, when adjusted at normal temperature and used
for high temperature, the set pressure value at normal temperature
should be slightly higher than the required opening pressure value.
How high is related to valve structure and material selection
should be based on the manufacturer's instructions.
⑥ The conventional safety valve is used to fix the additional back
pressure. When the opening pressure is adjusted after the
inspection (the back pressure is atmospheric pressure at this
time), the setting value should be the required opening pressure
minus the additional back pressure.
