PM1-32-40,PM3-50-65-DN100,027F3018 Danfoss Pressure regulating valve

PM1-32-40,PM3-50-65-DN100,027F3018 Danfoss Pressure regulating valve Installation

Refrigerants
Applicable to all common non-flammable
refrigerants, including R717 and non-
corrosive gases/liquids dependent on
sealing material compatibility.
Flammable hydrocarbons are not
recommended. The valve is only
recommended for use in closed circuits. For
further information please contact Danfoss.
Temperature range
PM: –60/+120°C (–76/+248°F)
Pressure range
PM: The valves are designed for a max.
working pressure of 28 bar g (406 psi g).
Technical data
The PM 3 can be used in suction, liquid,
hot-gas and liquid/vapour lines.
The PM 3 regulates the flow of the
medium by modulation or on/off function,
depending on the control impulse from the
screwed-on pilot valves.
The PM 3 has three connections for pilot
valves: two in series, marked “S I” and “S II”,
and one in parallel with these two, marked
“P”, see figs. 2 and 3.
Schematic examples of pilot valves
connected to the PM can be seen in figures
5, 6, 7, and 8.
If only two pilot valves are necessary
for the function required, the third pilot
connection must be sealed with a blanking
plug (see fig. 5). A blanking plug is supplied
with the valve.
Regulating range
Dependent on pilot valves.
Opening differential pressure (∆p)
The PM main valve requires a minimum
opening differential pressure of 0.07 bar
(1 psi) to begin to open and 0.2 bar (2.8 psi)
to be completely open.
Note: The valve opens when differential
pressure against the direction of flow
occurs.

Installation
Flange set for the PM is delivered
separately. The valve must be installed
with the arrow in the direction of the flow
and the top cover upwards (fig. 4). The top
cover can be rotated 4 × 90° in relation to
the valve body.
The valve is fitted with a spindle for manual
opening.
If an external pilot valve is used, the pilot
line must be connected to the upper side
of the main line so that any dirt and oil
from the plant will not find its way into the
pilot line.
If the PM 3 is to be used as a solenoid valve
in a liquid line, external control pressure
cannot be recommended because it can
cause liquid hammer.
The valve is designed to withstand a high
internal pressure. However, the piping
system should be designed to avoid liquid
traps and reduce the risk of hydraulic
pressure caused by thermal expansion. It
must be ensured that the valve is protected
from pressure transients like “liquid
hammer” in the system.
Welding
If using welding flanges, only materials
and welding methods, compatible with
the flange material must be welded to the
flanges. The flanges should be cleaned
internally to remove welding debris on
completion of welding and before the
valve is inserted.
The valve housing and flanges must be
free from stresses (external loads) after
installation.
PM valves must not be mounted in systems
where the outlet side of the valve is open
to atmosphere. The outlet side of the valve
must always be connected to the system
or properly capped off, for example with a
welded-on end plate.