2/3 Port Valves for Fluid Control Model Selection 1

Transcription

1 / Port Valves for Control Model Selection Model Selection For product specifications such as maximum operating pressure differentials and operating temperature ranges, refer to the relevent pages of each product. Air, Inert gas Air, Inert gas VDW VCA VX VXE VX VXD VXZ VXP VQ0/0 VNA VNB Only low wattage, DC type Zero pressure differential operation For dry air, built-in One-touch Fittings /8 /4 0A /8 5A 0A / /4 ø6, ø8, ø0, ø 5A A /4 / F 40F 50F P.4 P.7 P.9 P.9 P.79 P.59 P.77 P.45 P.67 P.57 P.65 VDW VCA VX VXE VX VXD VXZ VXP VQ0/0 VNA VNB Vacuum Vacuum Low vacuum Medium vacuum High vacuum VDW VX VX, VXV VX VCW VX VNB XL XM, XY XVD Option: V, M Made to Order available Option: V, M Flow rate adjustment /8 /4 0A 5A 0A 5A /8 / /4 Vacuum KF: 6, 5, 40, 50, 6, 80; K: 6, 80 Vacuum KF: 6, 5, 40, 50, 6, 80; K: 6, 80 For VCR: /4; For swage lock: /4 A /4 / F 40F 50F P.4 P.9 P.79 P.9 P.45 P.96 P.65 Best Pneumatics No. 8 VDW VCW VXV XL XM/XY XVD Courtesy of Steven Engineering, Inc.-0 Ryan Way, South San Francisco, CA Main Office: (650) Outside Local Area: (800)

2 / Port Valves for Control Model Selection Model Selection For product specifications such as maximum operating pressure differentials and operating temperature ranges, refer to the relevent pages of each product. Water Water VDW VX VXE VX VCW VCB VXD VXZ VXP VXR VXH VNB Only low wattage, DC type Zero pressure differential operation Water hammer relief Only AC type, MPa /8 /4 0A /8 5A 0A / /4 5A A /4 / F 40F 50F P.4 P.9 P.9 P.79 P.45 P.9 P.59 P.77 P.45 P.57 P.67 P.65 Heated water Heated water VX VX VCB VXD VXZ VXP VXR VNB Option: E, P Option: E, P Option: E, P Zero pressure differential operation, Option: E, P Option: E, P Water hammer relief, Option: D /8 /4 0A /8 5A 0A / /4 5A A /4 / F 40F 50F P.9 P.79 P.9 P.59 P.77 P.45 P.57 P.65 VDW VX VXE VX VCW VCB VXD VXZ VXP VXR VXH VNB 4 Courtesy of Steven Engineering, Inc.-0 Ryan Way, South San Francisco, CA Main Office: (650) Outside Local Area: (800)

3 / Port Valves for Control Model Selection Model Selection For product specifications such as maximum operating pressure differentials and operating temperature ranges, refer to the relevent pages of each product. Oil Oil VDW VX VXE VX VCL VXH VXD VXZ VXP VXR VNA VNB Option: A, H Option: A, D, H, N Only low wattage, DC type, Option: A, H Option: A, D, H, N Only AC type,.5 MPa or less Option: A, D, H, N Zero pressure differential operation, Option: A, D, H, N Option: A, D, H, N Water hammer relief, Option: A, D /8 /4 0A /8 5A 0A / /4 5A A /4 / F 40F 50F P.4 P.9 P.9 P.79 P. P.67 P.59 P.77 P.45 P.57 P.57 P.65 Steam Steam VCS VX VX VXP VND Option: S, Q Option: S, Q Option: S /8 /4 0A /8 5A 0A / /4 5A A /4 / F 40F 50F P.9 P.9 P.79 P.45 P.45 VDW VX VXE VX VCL VXH VXD VXZ VXP VXR VNA VNB VCS VND 6 Courtesy of Steven Engineering, Inc.-0 Ryan Way, South San Francisco, CA Main Office: (650) Outside Local Area: (800)

4 / Port Valves for Control Model Selection 4 Model Selection For product specifications such as maximum operating pressure differentials and operating temperature ranges, refer to the relevent pages of each product. High pressure compressed air Remarks /8 /4 0A /8 5A / 0A /4 5A A /4 / F 40F 50F High pressure compressed air VX VXE VXH VCH4 MPa or less Only low wattage, DC type, MPa or less Only AC type, MPa or less Only G thread type, 5 MPa or less P.9 P.9 P.67 P.7 Only G thread type Coolant /8 /4 0A /8 5A / 0A /4 5A A /4 / F 40F 50F 65A 80A Coolant SGC VNC VNH P.7 P.99 P.409 VX VXE VXH VCH4 SGC VNC VNH Chemicals, Pure water /8 /4 0A /8 5A / 0A /4 5A A /4 / F 40F 50F Chemicals, Pure water Pilot LV LVM Female thread type, with fittings type available With fittings type, female thread type available P.457 P.8 Body ported: ; Base mounted: M6 Dust collector /8 /4 0A /8 5A / 0A /4 5A A /4 / F 40F 50F Dust collector VXF Dedicated for dust collector P.69 LV LVM VXF 8 9 Courtesy of Steven Engineering, Inc.-0 Ryan Way, South San Francisco, CA Main Office: (650) Outside Local Area: (800)

5 Solenoid Valve Flow Characteristics (How to indicate flow characteristics). Indication of flow characteristics The flow characteristics in equipment such as a solenoid valve, etc. are indicated in their specifications as shown in Table ().. Pneumatic equipment. Indication according to the international standards () Conformed standard 0 Table () Indication of Flow Characteristics Corresponding equipment Pneumatic equipment Process fluid control equipment ISO 658: 989 : Pneumatic fluid power Components using compressible fluids Determination of flow-rate characteristics JIS B 890: 000 : Pneumatic fluid power Components using compressible fluids How to test flow-rate characteristics () Definition of flow characteristics The flow characteristics are indicated as a result of a comparison between sonic conductance C and critical pressure ratio b. Sonic conductance C : Value which divides the passing mass flow rate of an equipment in a choked flow condition by the product of the upstream absolute pressure and the density in a standard condition. Critical pressure ratio b : Pressure ratio (downstream pressure/upstream pressure) which will turn to a choked flow when the value is smaller than this ratio. Choked flow Subsonic flow Standard condition Indication by international standard C, b () Formula for flow rate It is described by the practical units as following. When Av Other indications : The flow in which the upstream pressure is higher than the downstream pressure and where sonic speed in a certain part of an equipment is reached. Gaseous mass flow rate is in proportion to the upstream pressure and not dependent on the downstream pressure. : Flow greater than the critical pressure ratio : Air in a temperature state of 0 C, absolute pressure 0. MPa (= 00 kpa = bar), relative humidity 65%. It is stipulated by adding the (ANR) after the unit depicting air volume. (standard reference atmosphere) Conformed standard: ISO 8778: 990 Pneumatic fluid power Standard reference atmosphere, JIS B 89: 000: Pneumatic fluid power Standard reference atmosphere P + 0. b, choked flow P + 0. Q = 600 x C 9 (P + 0.) () 7 + t When P + 0. > b, subsonic flow P + 0. P + 0. b P Q = 600 x C (P + 0.) () b 7 + t S Cv Cv Conformed standard ISO 658: 989 JIS B 890: 000 JIS B 890: 000 Equipment: JIS B 87, 874, 875, 879, 88 ANSI/(NFPA)T..: 990 IEC6054--: 997 JIS B 005: 995 Equipment: JIS B 847, 847, 847 Q : Air flow rate [dm /min (ANR)], dm (Cubic decimeter) of SI unit are also allowed to be described by l (liter). dm = l Courtesy of Steven Engineering, Inc.-0 Ryan Way, South San Francisco, CA Main Office: (650) Outside Local Area: (800)

6 Solenoid Valve Flow Characteristics C : Sonic conductance [dm /(s bar)] b : Critical pressure ratio [ ] P : Upstream pressure [MPa] P : Downstream pressure [MPa] t : Temperature [ C] Note) Formula of subsonic flow is the elliptic analogous curve. Flow characteristics are shown in Graph () For details, please make use of SMC s Energy Saving Program. Example) Obtain the air flow rate for P = [MPa], P = 0. [MPa], t = 0 [ C] when a solenoid valve is performed in C = [dm /(s bar)] and b = According to formula, the maximum flow rate = 600 x x ( + 0.) x = 600 [dm /min (ANR)] Pressure ratio = = + 0. Based on Graph (), it is going to be if it is read by the pressure ratio as and the flow ratio to be b = 0.. Hence, flow rate = Max. flow x flow ratio = 600 x = 40 [dm /min (ANR)] Flow rate ratio b = P Equipment C, b P Q Pressure ratio (P + 0.) / (P + 0.) Graph () Flow characteristics (4) Test method Attach a test equipment with the test circuit shown in Fig. () while maintaining the upstream pressure to a certain level which does not go below 0. MPa. Next, measure the maximum flow to be saturated in the first place, then measure this flow rate at 80%, 60%, 40%, 0% and the upstream and downstream pressure. And then, obtain the sonic conductance C from this maximum flow rate. Besides that, substitute each data of others for the subsonic flow formula to find b, then obtain the critical pressure ratio b from that average. Pressure control equipment ød d Thermometer Pressure gauge or pressure convertor d ød Differential pressure gauge or differential pressure converter Flow control valve ød Air supply Filter Shut off valve 0d 0d d 0d d Flow meter Pipe for measuring Equipment temperature for test Pipe for measuring pressure in the Pipe for measuring pressure in the upstream side downstream side Fig. () Test circuit based on ISO 658, JIS B 890 Courtesy of Steven Engineering, Inc.-0 Ryan Way, South San Francisco, CA Main Office: (650) Outside Local Area: (800)

7 Solenoid Valve Flow Characteristics. Effective area S () Conformed standard JIS B 890: 000: Pneumatic fluid power Components using compressible fluids Determination of flow rate characteristics Equipment standards: JIS B 87: port solenoid valve for pneumatics JIS B 874: port solenoid valve for pneumatics JIS B 875: 4 port, 5 port solenoid valve for pneumatics JIS B 879: Silencer for pneumatics JIS B 88: Fittings of flexible joint for pneumatics () Definition of flow characteristics Effective area S : The cross-sectional area having an ideal throttle without friction deduced from the calculation of the pressure changes inside an air tank or without reduced flow when discharging the compressed air in a choked flow, from an equipment attached to the air tank. This is the same concept representing the easy to run through as sonic conductance C. () Formula for flow rate When P + 0., choked flow P + 0. Q = 0 x S 9 (P + 0.) () 7 + t When P + 0. >, subsonic flow P + 0. Q = 40 x S 9 (P + 0.) (P P) (4) 7 + t Conversion with sonic conductance C: S = 5.0 x C (5) Q : Air flow rate[dm /min(anr)], dm (cubic decimeter) of SI unit are also allowed to be described by l (liter) dm = l S : Effective area [mm ] P : Upstream pressure [MPa] P : Downstream pressure [MPa] t : Temperature [ C] Note) Formula for subsonic flow (4) is only applicable when the critical pressure ratio b is the unknown equipment. In the formula () by the sonic conductance C, it is the same formula as when b =. (4) Test method Attach a test equipment with the test circuit shown in Fig. () in order to discharge air into the atmosphere until the pressure inside the air tank goes down to MPa (0. MPa) from an air tank filled with the compressed air at a certain pressure level ( MPa) which does not go below MPa. At this time, measure the discharging time and the residual pressure inside the air tank which had been left until it turned to be the normal values to determine the effective area S, using the following formula. The volume of an air tank should be selected within the specified range by corresponding to the effective area of an equipment for test. In the case of JIS B 87, 874, 875, 879, 88, the pressure values are in parentheses and the coefficient of the formula is.9. V Ps S =. log0 ( ) (6) t P + 0. T S : Effective area [mm ] V : Air tank capacity [dm ] t : Discharging time [s] Ps : Pressure inside air tank before discharging [MPa] P : Residual pressure inside air tank after discharging [MPa] T : Temperature inside air tank before discharging [K] Air supply Thermometer Pressure control equipment Filter Shut off valve Air tank Pressure switch Control circuit Pressure gauge or pressure convertor Timer (Clock) Pressure recorder Fig. () Test circuit based on JIS B 890 Power supply Solenoid valve Equipment for test Courtesy of Steven Engineering, Inc.-0 Ryan Way, South San Francisco, CA Main Office: (650) Outside Local Area: (800) Rectifier tube in the upstream side Rectifier tube in the downstream side

8 Solenoid Valve Flow Characteristics. Flow coefficient Cv factor The United States Standard ANSI/(NFPA)T..: 990: Pneumatic fluid power Flow rating test procedure and reporting method for fixed orifice components Defines the Cv factor of flow coefficient by the following formula which is based on the test conducted by the test circuit analogous to ISO 658. Q Cv = (7) P (P + Pa) 4.5 T P : Pressure drop between the static pressure tapping ports [bar] P : Pressure of the upstream tapping port [bar gauge] P : Pressure of the downstream tapping port [bar gauge]:p = P P Q : Flow rate [dm /s standard condition] Pa : Atmospheric pressure [bar absolute] T : Upstream absolute temperature [K] Test conditions are < P + Pa = 6.5 ± 0. bar absolute, T = 97 ± 5K, 0.07 bar P bar. This is the same concept as effective area A which ISO 658 stipulates as being applicable only when the pressure drop is smaller than the upstream pressure and the compression of air does not become a problem.. Process fluid control equipment () Conformed standard IEC6054--: 997: Industrial process control valves. Part : Flow capacity, Section Three-Test procedures JIS B 005: 995: Test method for the flow coefficient of a valve Equipment standards: JIS B 847: Solenoid valve for water JIS B 847: Solenoid valve for steam JIS B 847: Solenoid valve for fuel oil () Definition of flow characteristics Av factor: Value of the clean water flow rate represented by m /s which runs through a valve (equipment for test) when the pressure difference is Pa. It is calculated using the following formula. ρ Av = Q (8) P Av : Flow coefficient [m ] Q : Flow rate [m /s] P : Pressure difference [Pa] ρ : Density of fluid [kg/m ] () Formula of flow rate It is described by the practical units. Also, the flow characteristics are shown in Graph (). In the case of liquid: Q =.9 x 0 P 6 Av (9) G Q : Flow rate [l/min] Av : Flow coefficient [m ] P : Pressure difference [MPa] G : Relative density [water = ] In the case of saturated aqueous vapor: Q = 8. x 0 6 Av P(P + 0.) (0) Q : Flow rate [kg/h] Av : Flow coefficient [m ] P : Pressure difference [MPa] P : Upstream pressure [MPa]: P = P P P : Downstream pressure [MPa] Courtesy of Steven Engineering, Inc.-0 Ryan Way, South San Francisco, CA Main Office: (650) Outside Local Area: (800)

9 Solenoid Valve Flow Characteristics Conversion of flow coefficient: Av = 8 x 0 6 Kv = 4 x 0 6 Cv () Here, Kv factor : Value of the clean water flow rate represented by m /h which runs through a valve at 5 to 40 C, when the pressure difference is bar. Cv factor (Reference values): Figures representing the flow rate of clean water by US gal/min which runs through a valve at 60 F, when the pressure difference is lbf/in (psi). Value is different from Kv and Cv factors for pneumatic purpose due to different test method. Saturated steam flow rate Q0 [kg/h] (when Av = x 0 6 [m ]) Example P = MPa P = MPa Graph () Flow characteristics Example ) Obtain the pressure difference when water 5 [l/min] runs through a solenoid valve with an Av = 45 x 0 6 [m ]. Since Q0 = 5/45 = 0. [l/min], according to Graph (), if reading P when Q0 is 0., it will be 0.0 [MPa]. Example ) Obtain the saturated steam flow rate when P = [MPa], P = [MPa] with a solenoid valve with an Av =.5 x 0 6 [m ]. According to Graph (), if reading Q0 when P is and P is 0.008, it is [kg/h]. Hence, the flow rate Q = x.5 =.05 [kg/h]. (4) Test method Attach a test equipment with the test circuit shown in Fig. (). Next, pour water at 5 to 40 C, then measure the flow rate with a pressure difference of MPa. However, the pressure difference needs to be set with a large enough difference so that the Reynolds number does not go below a range of 4 x 0 4. By substituting the measurement results for formula (8) to figure out Av. Thermometer P = 0. MPa Upstream pressure P = MPa P = MPa P = 0. MPa P = 0. MPa Pressure differential P [MPa] Test range P = MPa Example Water flow rate Q0 [l/min] (When Av = x 0 6 [m ]) Pressure tap Equipment for test Pressure tap Throttle valve in the upstream side Flow meter d 6d Throttle valve in the downstream side 0d 0d 4 Fig. () Test circuit based on IEC6054--, JIS B 005 Courtesy of Steven Engineering, Inc.-0 Ryan Way, South San Francisco, CA Main Office: (650) Outside Local Area: (800)

10 Flow Characteristics Note) Use this graph as a guide. In the case of obtaining an accurate flow rate, refer to pages 0 through to 4. For Air Downstream pressure of valve (P) MPa VX VX VX VX 4 VX 50 VX VX Upstream pressure of valve P Approx..0 MPa ,000, , ,000,50 Flow rate Q l/min (ANR) Subsonic Critical pressure Sonic ø ø ø4.5 ø6 ø8 ø0 ø0 How to read the graph The sonic range pressure to generate a flow rate of 500 l/min (ANR) is P Approx. MPa for a ø6 orifice (VX 4 ) and P Approx. 0. MPa for a ø4.5 orifice (VX ). For Saturated Steam Downstream pressure of valve (P) MPa [66] (79) [664] (8) [66] (74) [66] (70) [660] (64) [658] (58) [656] (5) [654] (4) [650] () [646] (0) Upstream pressure of valve P Approx..0 MPa Subsonic Critical pressure Sonic VX VX VX VX 4 VX 50 VX VX Flow rate Q kg/h ø ø ø4.5 ø6 ø8 ø0 ø0 Figures inside [ ] indicate the saturated steam holding heat (kcal/kg). Figures inside ( ) indicate the saturation temperature ( C). How to read the graph The sonic range pressure to generate a flow rate of 5 kg/h is P Approx. MPa for ø4.5 orifice (VX S), P Approx. MPa for ø orifice (VX S), and P Approx. MPa for ø orifice (VX S). The holding heat slightly differs depending on the pressure P, but at 5 kg/h it is approximately 9700 kcal/h. Courtesy of Steven Engineering, Inc.-0 Ryan Way, South San Francisco, CA Main Office: (650) Outside Local Area: (800)

11 Flow Characteristics For Water Flow rate Q l/min VX 60-0 ø VX 60- ø0 VX 4 ø6 VX 50 ø8 VX ø4.5 VX ø VX ø (0.008) (0.0054) 0.0 (0.07) 0.05(0.07) Pressure differential P = (P P) MPa How to read the graph When a water flow of l/min is generated, P Approx MPa for a valve with ø orifice (VX,, ). 6 Courtesy of Steven Engineering, Inc.-0 Ryan Way, South San Francisco, CA Main Office: (650) Outside Local Area: (800)