Danfoss SFA 15 Safety Valve Installation Instructions

Refrigerants

The SFA 15 valve is applicable to all common non-flammable refrigerants, including R717 and non-corrosive gases/liquids, dependent on sealing material compatibility. Special types are required for flammable hydrocarbons. The valve is recommended for use in closed circuits only. For further information, please contact Danfoss.

Temperature and Pressure Range

Temperature Range: SFA 15: -30/+100°C (-22/+212°F).

Pressure Range: The valve is designed for a maximum working pressure of 40 bar g (580 psi g). Danfoss Industrial Refrigeration A/S supplies safety valves adjusted for a certain pressure (indicated on the ID-plate) and sealed. Danfoss Industrial Refrigeration guarantees correct pressure as long as the seal remains unbroken.

Installation

The valve should be installed with the spring housing upwards (Fig. 1). When mounting the safety valve, it is important to avoid the influence of thermic and dynamic stress (vibrations) (Fig. 2). The outlet pipe of the valve must be designed to prevent dirt from penetrating into the valve (Fig. 3). For valves with the outlet in the open air, an oil-filled U-pipe is an efficient protection against the entrance of water and dirt (Fig. 4).

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. It must be ensured that the valve is protected from pressure transients like "liquid hammer" in the system.

Welding

If welding fittings are applied, these should be dismounted during the welding process (Fig. 5). Only materials and welding methods compatible with the flange material must be welded to the flange. Avoid welding debris and dirt in the threads of the housing and pipes.

Assembly

Remove welding slag and dirt from tubes and housing before the valve is mounted. Mount the valve as shown in Fig. 6.

Colours and Identification

The valves are Zinc-Chromated in the factory. If further corrosion protection is required, it can be painted. Precise identification of the valve is made via the ID-plate on the valve housing. 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.

Danfoss can accept no responsibility for possible errors in catalogues, brochures and other printed material. Danfoss reserves the right to alter its products without notice. This also applies to products already on order provided that such alterations can be made without subsequent changes being necessary in specifications already agreed.

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Diagram Descriptions

Fig. 1: Illustrates the correct orientation for installing the valve with the spring housing upwards.

Fig. 2: Shows the importance of avoiding thermic and dynamic stress (vibrations) during mounting.

Fig. 3: Depicts how the outlet pipe should be designed to prevent dirt from entering the valve.

Fig. 4: Suggests using an oil-filled U-pipe for protection against water and dirt for valves with open outlets.

Fig. 5: Indicates that welding fittings should be dismounted during the welding process.

Fig. 6: Shows the assembly of the valve, including connection sizes: SFA 15: DN2 = 20 (3/4 in.) and SFA 15: DN1 = 15 (1/2 in.).