Pneumax - Hauptkatalog Page 1074
Commercial customer offer**Top sellers from Pneumax GmbH
Solutions for pneumatic automation General Catalogue Appendix Dimensioning The experimental determination of the valve coefficient C & b is carried out with compressed air following standardised procedures and according to the scheme below. CETOP test circuit A B C D E F G H L M1,M2 MΔP Compressed air generator. Pressure regulator to set upstream pressure P1. Shut off valve. Temperature sensor to check upstream temperature t 1, positioned in a low velocity area. Pipe where the upstream pressure is measured. Test valve. Pipe where the downstream pressure is measured. Flow regulator to adjust the downstream pressure P2. Flow meter. Pressure measuring equipment for upstream and downstream. Pressure drop measuring equipment assuming P1-P2< 1 bar. Pipes E & G, used to measure the valve upstream and downstream pressure, must be sized according to the standard’s specifications and change in size depending on the valve port sizes; the position of the connection at which the measurements are taken depends on the pipe’s inner diameter. Conductance C is determined with the following equation, measuring the critical flow rate Q* through the valve, where upstream pressure P1 is constant and greater than 3 bar. [2] Pressure critical ration b can be calculated using the following equation: APPENDIX A [3] Considering a given constant pressure P1 it is necessary to proceed measuring the flow rate Q' corresponding to a pressure drop DP = P1-P2 = 1 bar. Equation 3 is used to calculate the critical ratio as it is difficult to experimentally identify the exact pressure P*2 at which the flow becomes sonic. The values of both the conductance C and the critical ratio b are experimentally calculated and are the average of the results obtained. Equation [1] is used to calculate the flow in subsonic conditions P2>b·P1 when values C ; b and the valve working conditions (P1, P2, T1) are known. Under sonic conditions , P2£ b · P1 the equation can be simplified and the maximum flow rate can be calculated as follows: Q* = C · P1 · kt [4] HYDRAULIC COEFFICIENT KV The hydraulic coefficient allows, using the equation. The calculation of the flow rate of a fluid through a valve. [5] where: is the fluid flow rate in l/min is the pressure drop inside the valve calculated in bar (P1 - P1) is the fluid density calculated in Kg/dm³ is the hydraulic coefficient calculated in Using these measurement units the flow rate coefficient Kv represents the flow rate (in liters) of water across the valve with a pressure drop of 1 bar. The measurement are carried out using the standardised circuit below on which the connection ports are positioned according to the pipe inner bore size (norm VDE/VDI 2173). VALVE UNDER TEST A|5 Overall dimensions and technical information are provided solely for informative purposes and may be modified without notice.
1106 Pages | Valid until 06/2025 | Previous page | Next page
Choose your language
Legal issues
The manufacturer is exclusively responsible for the content, price and article details of the products and offers presented in the catalogues. Subject to technical and optical changes by the manufacturer and errors excepted.
Request form for special products
The ToolTeam® Procurement Service
Are you looking for products that are shown in the catalogue but cannot be purchased directly online?Our procurement service will be pleased to make you a non-binding and individual offer.