9. Referring to the following screw tightening rotation sequence, securely tighten the three
Allen screws (35), that connect the valve cap (32) to the valve plunger body (17). One at
a time, tighten each screw to first torque. Then continue with the next torque value until
the final value is reached.
a. Finger tighten
b. 20 inch-pounds (2.3 Nm)
c. 40 inch-pounds (4.5 Nm)
d. 60 inch-pounds (6.8 Nm)
10.Tighten the three Allen screws (16) that secure the plunger valve body (13) to the cylinder
base (14) to approximately 30 to 40 inch-pounds (3.4 to 4.5 Nm).
BE CERTAIN ALL ALLEN SCREWS ARE SECURELY TIGHTENED. DO NOT
OVERTIGHTEN.
4.5.12
Model 20 High Temperature Valve Specifications
Internal loop sample size:
2 μl standard. (Other sizes are available on special request.)
External loop sample size:
170 μl standard. (Other sizes are available on special request.)
Sample filter:
5 μm recommended (not furnished with valve).
Maximum operating temperature:
150°C (300°F) at 3450 kPa (500 psig) maximum standard
234°C (450°F) at 690 kPa (100 psig) maximum for special applications
Maximum leak rate between ports:
Less than 1 μl per minute between ports.
Material in contact with sample:
316 stainless steel. Other materials are available on special request.
Connection size and type:
1.6 mm (
1
/
16
") O. D. tubing, with Swagelok® fittings
Actuating air:
345 kPa (50 psig) instrument air standard. 550 kPa (80 psig) required for oper‐
ating pressure above 1380 kPa (200 psig). Helium or nitrogen may be substituted
for air.
Total switching time:
150 ms (total time from initiation of command signal to completion of change in
valve state)
Body size:
70 mm (2
3
/
4
") diameter by 70 mm (2
3
/
4
") height
Mounting:
Clamp type
Other:
A helium, hydrogen, or nitrogen purge may be used (an external supply of low
pressure helium is required).
Valves
4.5 Model 20 HT Valve
Maxum II Valves and Oven Components
80
Service Manual, 10/2018, A5E42019844001
