User Manual

THEORY OF OPERATION Stackable LCC/LCD Oven Owner’s Manual
20 Version 1.1
Copyright © 2012 by Despatch Industries.
All rights reserved. No part of the contents of this manual may be reproduced, copied or transmitted in any form or by any
means including graphic, electronic, or mechanical methods or photocopying, recording, or information storage and
retrieval systems without the written permission of Despatch Industries, unless for purchaser's personal use.
recommends changing the filter when the pressure is 1” w.c. greater than when the filter was first
installed (Refer to section 4.3 for filter replacement).
Since pressure can be affected by many factors involved in the
installation, it is important to record the pressure of a new filter as
a baseline. Recorded pressure readings allow for new readings to
be periodically checked against this baseline. Use Table 2 for
recording this information (See Section 8.1 for a blank
worksheet).
For a nitrogen atmosphere oven, pressure readings also give an
indication of the integrity of the seals. If the pressure recorded in
Columns D or E decrease over time, inspect the oven seals.
Table 2. HEPA Filter Pressure Reading Worksheet.
A
B
C
D
E
F
Date
Comments
Pressure
(inches of
water)
8
Pressure with:
150 SCFH (LCC1-
16); 200 SCFH
(LCC1-51) nitrogen
purge
9
Pressure with:
75 SCFH (LCC1-
16); 150 SCFH
(LCC1-51) nitrogen
maintain9
Oven
Temperature
Typical
Values
2-3”
1.5-2” above value
in Column C
0.5-1” above value
in Column C
60°C
Filter first
installed
8
With Purge and Maintain valves off for a nitrogen atmosphere oven. Cooling fan off for an air
atmosphere oven.
9
For a nitrogen atmosphere oven only.
Figure 4. Magnehelic Pressure
Gauge Measures Pressure in front of
the HEPA filter.