9909 Average Temperature Sensors
The 9909 Average Temperature Sensor (ATS) is a multiple element resistance temperature device designed to provide the average product temperature in large bulk liquid storage tanks.
The 9909 ATS provides an
accurate means of measuring the temperature of the
product in accordance with API 2543 standard.
A combined level and temperature instrumentation
solution improves management of your inventory, such
as crude oils, fuel oils, diesel fuels, gasolines and liquid
gases. Overall efficiency can be increased, whether the
facility is a refinery, chemical plant tank farm or
distribution terminal.
- Multiple element resistance temperature sensor
- Superior temperature accuracy in stratified service
- Provides overall average tank product temperature
- Suitable for most low and medium pressure tanks
- Fixed, floating and covered floating roof kits
- Operating temperature ranges to +392 °F (+200 °C)
- Flexible 316 S.S. or monel sheath over copper elements
- Accurate to +/- 0.25 °F (+/- 0.14 °C)
Operation
The sensor consists of between six and 10 graduated lengths of loop wound resistance elements housed in a flexible 316 Stainless Steel or Monel sheath. Each copper element, regardless of length, has a resistance of 100 Ohms at +77 °F (+25 °C). Each element measures resistance as it varies with the change in product temperature. The longest totally submerged element gives the best average temperature and is selected by the connected temperature transmitter or converter. As the temperature transmitter needs to know the product level in order to select the correct element, Varec recommends the 9909 ATS as one part of an overall inventory management system.
The 9909 ATS may be installed on fixed roof, internal or external floating roof storage tanks and pressurized tanks, such as spheres and bullets, up to a maximum working pressure of 50 psi (344 kPa).
In-Service and Out-of- Service Installations
Varec recommends fixing/weighing the end of the averaging bulb to reduce its movement in the tank in order to provide more accurate readings. For in-service installations, a weight (3" in diameter)may be attached to the bottom of the averaging bulb using a 9/32" (7 mm) diameter connector. For out-of-service installations, this connector may also be used to attach to a bracket that is welded to the bottom of the tank.
Standpipes and Thermowells
Floating roof tanks may utilize a perforated standpipe to house the 9909 ATS. If a thermowell is to be used with the 9909 ATS, Varec suggests the use of a 2" (51 mm) schedule 40 thermowell. A non-perforated thermowell is generally oil-filled to improve thermal response to product temperature changes.
Mounting the 9909 ATS
Two 4 " (100 mm) diameter MSS flanges with gaskets are installed, one on each side of the tank roof. The averaging bulb ¾ " (19 mm) threaded tube is then screwed into the MSS flange. This method requires access to the inside of the tank. An alternate method is to order the unit with an ANSI flange, which is available up to 4" (100 mm). The standard lead length of a flange is 4.9 ft (1.5 m); please consult the factory for any non-standard lead lengths. For use with floating roof tanks, an additional nylon bush may also be required to ensure the floating roof moves seamlessly along the temperature probe.
Product Options
- Housing material: 316 SS or Monel
- Service temperatures: -17...+100°C (0...212°F) or -17...+200°C (0...392°F)
- Element type: 100 Ohm wire wound copper or DIN platinum characterized copper
- Process connection: 2" 150 lb RF Flange C.S. or Type 1 3/4" NPS hex nut/washers
- Anchor weight: Steel (3" or 2" min. flange) or standard, stainless steel (3" or 2" min. flange)
- Leadwire length at connection head: 5 ft leadwire or NEMA VII connection to head and terminal strips
- Tank height: 0...50 ft (0...17 m)
