PW3S RECTANGULAR MULTI-BLADE SPECIAL DAMPER Characteristics: A rectangular multi-blade damper with backward blades and a high level of tightness used for airflow control or closing. Controlled manually or by an electric actuator. It is possible to mount them in air handling units, within walls or normally within ventilation ducts. Operating temperature: -20 °C to +90 °C, (+50 °C for the actuator version). Design The housing and the blades are made of galvanised steel or stainless steel 1.4301 (in accordance with EN 10088). The blades have rubber seals (EPDM). The sealing inserts and drive mechanism elements are made of plastic. In accordance with PN-EN 1751, the design of the damper ensures baffle tightness within the range of class 3 and the highest possible housing leakage class C. Special sealing inserts mounted at the blade ends guarantee high baffle integrity, as well as side seals – the integrity of the whole housing. The individual blades are driven by a system of plastic levers and steel tie rods in a backward arrangement. The blades are fitted with plastic slide bearings. The assembling frame has a Figure 2. PW3S damper blade. width of 30 mm. It can be powder coated to any colour from the RAL palette. Manufacturing Versions PW3S multi-blade dampers with backward blades are designed for airflow control and closing in rectangular ventilation ducts. Figure 1. PW3S damper dimensions. Figure 2. PW3S damper blade. Standard dimensions of PW3S dampers: Width A = 200÷1400 mm (1 mm interval) Height B = 200÷2000 mm (100 mm interval) Drive: T1 – Damper with an actuator T2 – Damper with a manual mechanism T3 – Damper with an extended axle (for the actuator installation) Due to the width of the blade, the recommended height is B = n x 100, where n is the number of the blades. It is possible to make the damper another height (1 mm interval), with a masking frame covering the clearance partially. If it is necessary to use a damper larger than 1400 x 2000 mm, a combined damper consisting of two smaller dampers is made. The dampers have independent driving axles (two separate manual mechanisms or actuators on opposite sides). Other sizes and variants are available for special order. Rectangular multi-blade spec

Technical Data Table 1. Types of actuators and the net surface area for the PW3S damper in a fully open position. Height B, [mm] Table 2. Type of the actuator. without a spring Actuator torque Combined damper consisting of several smaller dampers. For a custom design – please contact Smay. (*) - Combined damper 2 x … Nm requires the use of two smaller dampers with separate actuators. The given actuator types can be used in several variants differing in communication and supply voltage. Rectangular multi-blade special dampe

Chart 1. Pressure loss for the PW3S damper in a fully open position. Pressure loss in a custom-height damper (with a masking frame covering the clearance partially) is comparable to the pressure loss for the nearest smaller standard height damper read from Chart 1. Δp (600 x 460) ≈ Δp (600 x 400) from Chart 1 Chart 2. Air leaks through the PW3S damper baffle (in a fully closed position). Rectangular multi-blade special damper Chart 3. Air leaks through the PW3S damper housing (in a fully closed positio

When ordering, please provide information as follows: PW3S<K> - <A>x<B> - W<W> - <P><RAL> - <KK> - T<N> - <KL> * Optional values, if not specified, the default values will be used “additionally provide: actuator manufacturer (Siemens/Belimo); supply voltage (24 V or 230 V), safety functions (with or without spring return), operation of the return spring (spring closes the damper or spring opens the damper), type of control (close/open, 3-point, analog), whether the actuator is to have auxiliary contacts. Rectangular multi-blade special damper