Azbil Corporation No. SS2-VFR100-0100 - 3 - Selection guide for the multi-hole plate (anti-cavitation and low noise specification) 1. selection standard . For incompressible fluid (liquid) Cavitation number (Kc value) will be calculated according to the operation condition. The multi-hole plate is recommended (select the specification) if the calculated Kc value is over 0.55. It is not applicable for compressible fluid (gas/steam). P1: Valve primary side pressure P2: Valve secondary side pressure Pv: Saturated vapor pressure of fluid according to inflow side temp. condition ..P = P1 - P2 : Valve differential pressure . For compressible fluid (gas/steam) Calculate predictive noise level. The multi-hole plate is recommended if predict noise level is higher than the regulation level. 2. Noise control efficiency of the multi-hole plate The figure below shows differences in the noise occurring based on the structures of the standard type and multi-hole plate type model VFR. Noise that occurs when controlling the flow differs depending on the structures of the valve body and inner valve. The multi-hole plate type model has a maximum noise suppression of 7 dBA. Note) *1: SUS316 Stellite type is used for valves for gas or steam service. *2: SUS316 Stellite type is used for valves for thermal medium service. *3: P6610CH (graphite packing) + P6528 (carbon yarn packing) is used for valves for thermal medium service. *4: SUS316 PTFE seat (glass reinforced) type is applicable to fluid temperatures -30 to +200°C (standard type) or -60 to -31°C (low temperature type). *5: Figure 1 Noise control efficiency (dBA) Table 1 Body / trim material combination and operating temperature ranges (°C) Components Material Valve body JIS SCPH2 SCS13A SCS14A ASTM A216WCB A351 CF8 A351 CF8M Trims Valve plug SCS24 SCS14 Stellite SCS14 Stellite SCS14 Stellite Seat ring SUS630 SUS316 (*4) PTFE seat SUS316 SUS316 (*4) PTFE seat SUS316 SUS316 Stellite SUS316 (*4) PTFE seat SUS316 SUS316 Stellite SUS316 (*4) PTFE seat Seat retainer SUS630 SUS316 Brain bearing SUS440C (*1, *2) SUS316 Stellite Main bushing SUS440C (*1, *2) SUS316 Stellite Valve stem SUS316 (*2) Key SUS630 Stellite Spring SUS316 Packing ring SUS316 Packing PTFE yarn, Graphite packing + carbon yarn packing *3 Packing follower SUS316 Packing flange SUS304 Bolts and nuts for packing flange SCM3 / SUS304 (For packing) Gasket Spiral type*5 (Installed between seat ring and seat retainer) Temperature range -5 to 350°C -60 to 350°C 0 2 4 6 8 10 12 14 16 18 20 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 Cavitation Number Kc SPL (dBA) 7dBA Standard model VFR multi-hole plate model VFR Multi-hole plate Multi-hole plate (model HRL) Model VFR-wafer type (Multi-hole plate built-in type) Model VFR-wafer type +Multi-hole plate (Model HRL assembled) Kc = ..P P1 - Pv Temperature range Gasket material General -60°C < t < +350°C SUS316 with inorganic paper as filler material Oil free -60°C < t < +230°C SUS316 with PTFE as filler material +230°C < t < +350°C SUS316 with graphite as filler material 4 2