PTI SENTRY 1510 User Manual

11984 Rev 01 Page 4 of 8
1.3 Requirements
4. A “carrier” supply to ensure there is enough flow to provide control, even in the
presence of very low gas flow (for example, during steam processes where
much of the process effluent is condensed prior to the controller)
Figure 1-2 shows how the nitrogen is distributed to perform these functions.
Sufficient nitrogen is critical to optimum operation. Without sufficient nitrogen, the
transducer can be damaged and contaminants may back stream from house
exhaust. In addition, if process flow rates drop significantly, the controller
performance may be degraded.
House Exhaust Requirements
Minimum house exhaust requirements are given in Appendix B. However, in many
installations, less house exhaust is required, and in some specific installatios,
additional house exhaust is required. This section allows the user to calculate the
amount of exhaust required for a specific installation.
Calculating minimum house exhaust requirements to operate a “sealed” vertical
furnace at a specified Process Pressure is a relatively simple process; however,
careful attention must be paid to the exhaust path configuration when doing this
calculation. Figure 1-3 is intended to be a guide to assist the user in making this
calculation. This calculation consists of the basic formula:
P
Sense
- (P
Exit
+ P
Controller
+ P
Facility
) = Minimum House Exhaust Requirement
where;
P
Sense
= Process Pressure or Set-Point within the Sealed Chamber.
N
2
R
R
V
V
Nitrogen
Bias Flow
Nitrogen
“Air”
Bearing
Sense
Line
Purge
Process Pressure
Sense Line
(to process tube)
Pressure
Transducer
Figure 1-2: Nitrogen is used in three different places in the SENTRY 1510.

PTI SENTRY 1510 Specifications

General

Brand	PTI
Model	SENTRY 1510
Category	Controller
Language	English