Model 50 Valve Specifications; Table 4-8 Configuration; Table 4-9 Performance And Requirements - Siemens Maxum II PD PA AP Service Manual

Valve Reinstallation
1. Reinstall the valve in the oven and connect all tubing.
Note
Best practice is to seat the fittings in a Valco fitting and not in the Model 50 Valve ports.
This will help increase the life of the valve and reduce the chances of causing the center
plate to bulge from over tightening the fittings. See the AUTOHOTSPOT section for
instructions.
2. Power up and check for leaks. Verify valve operation by running chromatograms.
4.3.5

Model 50 Valve Specifications

Table 4-8 Configuration
Valve Type
Number of Ports
Flow Paths
Table 4-9 Performance and Requirements
Sample Types
Actuation Gas
Switching Time
Sample Filtration
Maximum Actuation Pressure
Minimum Actuation Pressure
Maximum Port Pressure
(Carrier or Sample)
Minimum Port Pressure
(Carrier or Sample)
Pressure Drop
Maximum Temperature
Carrier Gas Flow
Mean Time Between Failures
Maxum II Valves and Oven Components
Service Manual, 10/2018, A5E42019844001
Double-acting, pneumatically operated
10
On state: flow between ports 1 & 10, 2 & 3, 4 & 5, 8 & 9
Off state: flow between ports 1 & 2, 3 & 4, 5 & 6, 7 & 8, 9 & 10
Note: flow between ports 6 & 7 is always blocked
Vapor samples only, free of particulates
Inert gas, particulate free
20 ms (Typical in Maxum gas chromatographs.) In other uses, actual switching time
is dependent on the type of solenoids used to deliver the pneumatic signal to the valve
and the size of the pneumatic tubing to the valve.
5 micron
690 kPa (100 psig)
140-175 kPa (20-25 psig) higher than maximum carrier gas or sample gas pressure
515 kPa (75 psig); contact factory for higher pressure options
35 kPa (5 psi)
< 35 kPa (5 psi) for 200 scc/min (air) Pressure drop was measured in air at room
temperature with flow from port to port. Actual pressure drop will vary with temperature
and gas type. Pressure drop through the sample loop is dependent on the inside di‐
ameter and length of the sample loop.
120°C (248°F); contact factory for higher temperature options
0.3 ml/min to 40 ml/min; contact factory for higher flow options
>10 cycles at 60°C (140°F); >4×10
7
caused by particulates preventing the diaphragms from sealing against the center plate
or long term wear resulting in deformation of the diaphragms.
cycles at 150°C (300°F). Valve failure is typically
6
Valves
4.3 Model 50 Valve
53