MKS 1253D, Инструкция по эксплуатации

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Product Location and Requirements Chapter Two: Installation
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Product Location and Requirements
153 Unit: Heated Valves
The Type 153 unit is not designed to operate with a heated valve unless certain modifications are
made. Some installations require that the exhaust line and throttle valve be heated to prevent
exhaust vapors from precipitating out in the exhaust line. For these types of applications, contact
MKS Instruments, Inc.
System Considerations
For best pressure control, locate the pressure transducer and the exhaust valve as close as
practical to the process chamber. This minimizes the time constants associated with these items.
Use tubing that is less than 6 inches long and no less that ¼ inch diameter to connect the
transducer and chamber. If the distance must exceed 6 inches, then use a larger diameter tubing
to compensate for conductance losses.
Size of the 253 Valve
The 1253 unit controls an external 253 valve (not included). This valve can be sized for a wide
variety of applications. The size of the valve is dictated by the size of the vacuum exhaust line
and the range of conductance necessary for the pressure and flow rates being used. (Refer to the
253 data sheet for detailed information on the different valves available.)
Setup
Mounting the 153 Unit
The 153 unit can be mounted in a vacuum exhaust line with the proper fittings and connectors.
The 153 unit consists of a Type 253 exhaust valve with an electronic housing attached to the
motor plate.
Although the 153 unit was designed and tested to operate in the most extreme conditions (with
no air circulation and a heated valve at 80° C), it will operate cooler if the air slots in the side of
the housing are clear to allow convection air circulation. Typically, electronic components last
longer in cooler environments.
Mounting the 1253 Unit
You can mount the 1253 unit in any position. For optimum performance, mount the power
supply and 1253 unit near the valve. This reduces the length of cable necessary to connect the
valve to the unit and thereby reduces the amount of voltage loss in the valve drive cables. Refer
to the 253 valve Instruction Manual for directions on mounting the valve.