M20Ht Procedure - Cleaning Of Parts; M20Ht Procedure - Valve Cap Disassembly - Siemens Maxum II PD PA AP Service Manual

4.5.7

M20HT Procedure - Cleaning of Parts

All parts must be inspected for cleanliness, including catalyst or polymer buildup on the valve
cap. Before re-assembly, faces of the plunger valve body (17) should be wiped clean using
hexane, acetone, or methanol and a lint free cloth.
An ultrasonic cleaner filled with a recommended cleaning solvent or detergent is recommended
for cleaning all components. However, after cleaning, there must not be any remaining residue.
If cleaning solution becomes contaminated during cleaning, it must be replaced with an
uncontaminated supply.
A syringe and appropriate solvent can be used to flush the ports of the valve cap. This is
described in the procedure.
It is important for proper procedures to be used when cleaning valve and detector parts. All
foreign contamination adhering to the part should be removed using an appropriate cleaning
solvent, such as hexane, acetone, or methanol and a dust/lint free cloth. Use of an ultrasonic
cleaner is often helpful. After cleaning, it is necessary remove excess cleaning fluid from the
components by blowing with clean air or shaking. Components must be air dry before
reassembling.
It is possible and often better to use an appropriate detergent, such as Alconox® for cleaning
instead of solvent. However, after cleaning with a detergent, it is necessary to rinse the part
thoroughly with deionized water (distilled water is also acceptable) in order to remove detergent
residue. All water must then be removed by blowing with clean air or shaking. Components
must be completely dry before reassembling.
4.5.8

M20HT Procedure - Valve Cap Disassembly

1. Loosen the three Allen screws (35), holding the plunger valve body (17) to the valve cylinder
base (16). The screws should be loosened to the point that most of the spring pressure is
relieved (approximately 1/8" or 3.2 mm).
Do not remove the three Allen mounting screws at this time.
2. To remove valve cap (32), remove the three Allen screws (35) and six Belleville washers
(36) holding the valve cap (32) to the valve plunger body (17).
3. Remove the valve cap (32) from the plunger valve body (17).
Maxum II Valves and Oven Components
Service Manual, 10/2018, A5E42019844001
NOTICE
To prevent damage to the valve cap (32), do not place polished surface of the valve cap
against any abrasive surface. Place it on a lint free cloth free of foreign contaminants.
Valves
4.5 Model 20 HT Valve
73