Danfoss PM3 Installation guide

Installation Guide
Piot operated servo valves PM3 (80-125)
Installation
027R9526
Fig. 1
Danfoss
M27F0002
Nm kpm lbf-ft
Pos.
item
80 100 125
a 50
b 65
c 25
d 140
g 75 80 125
i 9
k 25 40 60
l 45 60 90
m 150 220 310
10 1 7.4
Table 1
027R9526
Fig. 2
Fig. 3
Fig. 4
© Danfoss A/S (RC-MDP/MWA), 2014-05 DKRCI.PI.HL0.C3.02 / 520H4520 1
Fig. 5
Fig. 6
Fig. 7
A
B
Fig. 8
2 DKRCI.PI.HL0.C3.02 / 520H4520 © Danfoss A/S (RC-MDP/MWA), 2014-05
Fig. 9
ENGLISH
Installation
Refrigerants
Applicable to HCFC, HFC and R717 (Ammonia). 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.
Mounting of valve flanges
When welding/soldering the flanges to the system piping use only materials and welding/soldering methods compatible with the flange material.
• Make sure that piping into which a valve/ flange is installed is properly supported and aligned square and plumb to the joining sections.
• Ensure that the finalized valve assembly is free of any stresses from external loads.
• Make certain that the heat affected zones (inside and outside) and the mating surfaces of gasketed joints are free of debris and rust and are in good condition.
• Use only new gaskets manufactured by Danfoss.
• Make sure that the bolts are adequately tightened in an alternating pattern.
• Use only original Danfoss stainless steel bolts provided with the valve. Stainless steel bolts offer corrosion protection and they ensure safe operation across the design operating range of the valve when installed properly.
Note: Stainless steel bolts have a
slightly lower yield strength compared to carbon steel bolts. Be careful not to over-tighten the bolts.
• Ensure that flanges / valves are properly pressure tested, leak tested, evacuated before charging with refrigerant in accordance with ANSI /IIAR 5, EN378-2 or ISO 5149-2.
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.
Colours and identification
The PM valves are Zinc-Chromated in the factory. If further corrosion protection is required, the valves can be painted. Precise identification of the valve is made via the ID plate on the top cover. The external surface of the valve housing must be prevented against corrosion with a suitable protective coating after installation and assembly.
Maintenance
Service
The PM valves are easy to dismantle and most of its parts are replaceable. When the bottom cover is removed, the strainer can be taken out for cleaning. Do not open the valve while the valve is still under pressure.
- Check that the gasket has not been damaged. Ideally, the gasket should be replaced.
- Check that the spindle is free of scratches and impact marks.
- If the teflon ring has been damaged, the parts must be replaced.
Assembly
Remove any dirt from the body before the valve is assembled. Check that all channels in the valve are not blocked with particles or similar.
Tightening
Tightening torques
See fig. 1 and table 1.
Always carry out this operation when the manual operation device has been in use (see fig 9)
1. Remove the cap (A) and tighten the
spindle (B) anticlockwise with 8 Nm (5.9 lb/ft)
2. Remount the cap (A) and tighten it
clockwise with 8 Nm (5.9 lb/ft)
Use only original Danfoss parts, including packing glands, O-rings and gaskets for replacement. Materials of new parts are certified for the relevant refrigerant.
In cases of doubt, please contact Danfoss.
Danfoss accepts no responsibility for errors and omissions. Danfoss Industrial Refrigeration reserves the right to make changes to products and specifications without prior notice.
The following text is applicable to the UL listed products PM3 (80-125)
Applicable to all common non-flammable refrigerants, including/excluding (+) R717 and to non-corrosive gases/ liquids dependent on sealing material compatibility (++). The design pressure shall not be less than the value outlined in Sec. 9.2 of ANSI/ASHRAE 15 for the refrigerant used in the system. (+++).
Protection of the ID plate when repainting the valve is recommended.
© Danfoss A/S (RC-MDP/MWA), 2014-05 DKRCI.PI.HL0.C3.02 / 520H4520 3
www.danfoss.com/ir
4 DKRCI.PI.HL0.C3.02 / 520H4520 © Danfoss A/S (RC-MDP/MWA), 2014-05
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