Installation Guide
Float Valve (High Pressure)
HFI
Installation
Refrigerants
Applicable to common non-flammable refrigerants, including R717 and non-corrosive gases/liquids dependent on sealing material compatibility. As standard, the float ball is designed for R717 with a density of 500 through to 700 kg/m³. For refrigerants with densities outside this range, contact Danfoss. Flammable hydrocarbons are not recommended. The valve is recommended for use in closed circuits only.
Temperature Range
HFI: -50/+80°C (-58/+176°F)
Pressure Range
The HFI valve is designed for a maximum pressure of PED: 28 bar g (407 psi g).
The float ball is designed for a maximum working pressure of 25 bar g (363 psi g).
If test pressure exceeds 25 bar g (363 psi g), the ball should be removed during testing.
Mounting
Mount the float valve horizontally with the outlet connection (pos. A) vertically downwards. The flow direction must be from the flanged inlet connection, as indicated by the arrows.
The valve is designed to withstand 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. Ensure the valve is protected from pressure transients like "liquid hammer" in the system.
Welding
Remove the float assembly before welding as follows:
- Dismount the end cover and remove the transport packing.
- After welding and assembly, the transport packing should be put back into place until the final destination of the unit is reached.
- Unscrew the screw (pos. C) and lift up the float assembly from the outlet.
- Weld the outlet connection (pos. A) into the plant as shown in figure 2.
- Only materials and welding methods compatible with the valve housing material must be welded to the valve housing.
- The valve should be cleaned internally to remove welding debris on completion of welding and before the valve is reassembled.
- Avoid welding debris and dirt in the housing.
NB! When demand is heavy at low temperature operation, check the velocity in the outlet branch. If necessary, the diameter of the pipe welded onto the outlet branch (pos. A) can be increased.
The valve housing must be free from stresses (external loads) after installation.
Assembly
Remove welding debris and any dirt from pipes and valve body before assembly.
Replace float assembly in the outlet connection and tighten the screw (pos. C). Check that the float assembly is fully seated and the float ball is positioned in the middle of the housing, so it can move without any restriction.
Remount the end cover with purge valve and pipe in the housing. NB! The ventilating pipe (pos. E) has to be placed vertically upwards.
In case an insert with a slide (version before 2007) is replaced by a present version, an extra threaded hole needs to be made in the outlet connection A to fix the screw (fig.1).
Tightening
Use a torque wrench to tighten the screws (pos. F). Tighten with a torque of 183 Nm (135 LB-feet). This torque specification is shown for securing the float assembly and the end cover.
Colours and Identification
The HFI valves are painted with a red oxide primer in the factory. The external surface of the valve housing must be protected against corrosion with a suitable protective coating after installation and assembly. Protection of the ID plate when repainting the valve is recommended.
The valve can be in a 'Fully closed' state with no orifice holes exposed, or 'Fully open' with orifice holes exposed.
Maintenance
Purging of Incondensable Gases
Incondensable gases might accumulate in the upper part of the float valve. Purge these gases by means of the purge valve (pos. G).
Replacement of Complete Float Assembly
Follow these steps for replacing a factory-adjusted complete float assembly:
- NB! Before opening up the float valve, the system must be evacuated and the pressure equalized to atmospheric pressure by using the purge valve (pos. G).
- Remove the end cover.
- Remove float valve assembly by untightening the screw (pos. C) and lifting up the complete float valve assembly.
- Place new float assembly in the outlet connection (pos. A) and tighten the screw (pos. C).
- Remount the end cover with purge valve and pipe on the housing. NB! The ventilating pipe (pos. E) has to be placed vertically upwards.
- Use a torque wrench to tighten the screws (pos. F). Tighten with a torque of 183 Nm (135 LB-feet).
- NB! Check that the purge valve is closed before you pressurize the float valve.
Use only original Danfoss parts for replacement. Materials of new parts are certified for the relevant refrigerant.
In cases of doubt, please contact Danfoss. Danfoss accepts no responsibility for possible errors and omissions. Danfoss Industrial Refrigeration reserves the right to make changes to products and specifications without prior notice.