Global Valves - BELIMO - #33

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ENG-93001-93621-08.04-1M • Printed in Switzerland • ZSD • Subject to technical modifications BC 33 Notes on project design Installation, mounting position and commissioning Separate delivery If the globe valve is delivered separately from the linear actuator, they can be assembled directly on site. Permissible insulation limit The permissible insulation limit on the bracket must not exceed: – X < 30 mm for NV – X < 70 mm for AV. Recommended mounting position The globe valves may be mounted either vertically (Fig. 1) or horizontally (Fig. 2). However, mounting the valves with the stem pointing downwards, i.e. upside down, is not recommended (Fig. 3). No special tools are needed for the installation. Full instructions are supplied with the valves and actuators. Commissioning Commissioning must not be carried out until the globe valve and linear actuator have been assembled in accordance with the instructions. If NV...-MFT actuator types are enclosed separately (e.g. H415B+NV24- MFT), make sure that the actuator is correctly mounted on the valve before the power supply is energized for the first time. Adaptation is only effected once automatically the first time the power supply is energized. If a valve is not mounted, the actuator reports a fault (the red LED is lit steadily). Fig. 1 Fig. 2 Fig. 3 Insulation limit X Insulation Direction of flow The prescribed directions of flow for specific applications must be adhered to. Flow characteristics of globe valves 2-way The flow characteristic is equal percentage, with a characteristic factor of n(ep) = 3. This ensures stable control behavior in the elevated part-load range. In the lower part of the opening range between 0 and 30% stroke the characteristic is linear. This ensures excellent control characteristics in the lower part of the load range as well (Fig. 1). 3-way The characteristic of control path A–AB is the same as that for 2-way globe valves. The bypass B–AB has the same kvs value as the control path. The bypass has a linear characteristic (Fig. 2). A AB B A AB B This direction of flow not allowed, 2-way This direction of flow not allowed, 3-way kv/kvs 100% 50% 0% 50% 100% A–AB B–AB kv/kvs 100% 50% 0% 50% 100% A–AB Stroke A AB B A AB B Stroke