Model 20 Valve; Basic Maintenance; Maintenance Considerations; Table 4-10 Dimensions - Siemens Maxum II PD PA AP Service Manual

Valves

4.4 Model 20 Valve

Table 4-10 Dimensions
Mounting
Actuation & Sample Connections
Dimensions
Weight
Materials of Construction
4.4 Model 20 Valve
4.4.1

Basic Maintenance

This section presents information to perform fault diagnostic testing, maintenance and repair
and installation of Model 20 valve. To assure optimum valve operation, a clean contaminant
free operating environment is required at all times.
Maintenance procedures for the Model 20 valve are divided into three types. These are:
diagnostic, mini-maintenance, and maxi-maintenance. Diagnostic procedures can determine
problems by a visual examination of valve. Mini-maintenance involves removal and cleaning
of the valve cap, which can be performed while the valve is installed in the analyzer. Maxi-
maintenance procedures are more involved and include complete disassembly of the valve.
In this manual, only diagnostic and mini-maintenance procedures are discussed. More detailed
maintenance procedures are discussed in other manuals; however, it is recommended that
the valve be returned to Siemens for service when more detailed maintenance is needed.
4.4.1.1

Maintenance Considerations

If customer maintenance personnel are not technically trained to repair the Model 20 valve on
site, it is recommended that the valve be returned to Siemens for service, repair, or direct
replacement.
To repair the valve on site, the customer must have the necessary maintenance tools and
replacement parts. Recommended valve spare parts, including the Model 20 repair kit (PN
K21000), can be obtained from Siemens.
When cleaning the Model 20 valve components, it is imperative that the maintenance be
performed in a clean and contaminant free facility. Components should be placed on a lint free
cloth to prevent impurities from contaminating the valve and its components. Hands should be
clean and free of contaminants. Presence of any foreign contamination can cause additional
valve problems after reinstallation.
All foreign contamination adhering to valve components must be removed using cleaning
solvent, such as hexane, acetone, or methanol and a dust/lint free cloth. After cleaning valve
cap and tubing, shake or blow with clean air the excess cleaning fluid from the individual
components. Ensure that the components are air dry before reassembling.
54
2 clearance holes for mounting screws (mounting brackets available as separate spare
part if desired)
1.6 mm ( / ") OD tubing with Valco® or Swagelok® fittings
1
16
Height: 33 mm (1 / ")
5
16
Body Diameter: 38 mm (1
Outside Diameter: 50 mm (2")
0.25 kg (0.5 lb)
Body: 316 stainless steel
Diaphragms: Teflon® coated stainless steel
/ ")
1
2
Maxum II Valves and Oven Components
Service Manual, 10/2018, A5E42019844001