Richards Thermocouple and Temperature Sensor Catalog 16

Straight Assemblies - Mounting Attachments

Metal Tube

Ceramic Tube

Adjustable Flange (AF) An adjustable flange is used to adjust the protection tube’s depth of insertion. In most cases the tube should extend into fluids at least six times the out side diameter of the tube. If the tube is going into a gas, it should extend a minimum of eight times the outside diameter of the tube. The adjustable flange can also be used to extend the connection head away from excessive heat or corrosive gases. A flange will not give a gas tight seal. If a gas tight seal is required, a Threaded Fitting ( TF ) or a Welded fitting (W ) should be used. On Ceramic tubes it is necessary to have a metal sleeve to mount the flange. This will prevent the tube from breaking when the set screw is tightened. This sleeve is normally made from high temperature #9 alloy (600). To add an adjustable flange to a metal or ceramic assembly, add ( AF ) to the end of the part number. Examples: Metal: 8K4-722-18-SH-AF (18”, #7 alloy metal tube assembly, and an adjustable flange.) Ceramic: 8K4-P11N9-6-18-SH-AF (18”, Mullite tube assembly, 6” #9 alloy sleeve, and an adjustable flange.)

1

Metal Tube

Ceramic Tube

2

Extensions (E) An Extension is used where it is not necessary to have the alloy pipe extend through the cool part of the furnace. By using a steel extension (or balance pipe), the total cost of the protection tube can be reduced. The extension also keeps the connection head out of any corrosive gases and away from excessive heat. Extensions can be added to metal or ceramic protection tubes. To add an extension to a metal or ceramic assembly, add ( E ) and the number of inches to the end of the part number. Examples: Metal: 8K4-722-18-E-12-SH (18”, #7 alloy metal tube assembly, and a 12” extension.) Ceramic: 8K4-P11F-18-E-12-SH (18”, Mullite tube assembly, and a 12” extension.)

Metal Tube

Threaded Fitting (TF) A Threaded Fitting has three threads; it is screwed on to the open end of a protection tube and then screwed into the furnace to give a gas tight seal. The third thread permits the tube to be extended beyond the fitting for mounting a terminal head. The replace- ment of a protection tube with a threaded fitting is less expensive than one with a welded bushing since only the tube needs to be changed. The standard outside thread size is 1 1/4” NPT. 1/2” NPT threaded fittings are standard outside threads on 1/4” and 1/8” pipe sizes. Other sizes can be ordered by specifying the size in 1/16ths of and inch. Example: A 1 1/2” x 1/2” 1/2” NPT thread fitting would be a TF2408 . See under “Accessories” for more details. To add a threaded fitting to a metal assembly, add ( TF ) to the part number. Example: Metal: 8K4-722-18-TF-6-SH (18”, #7 alloy metal tube assembly, Threaded Fitting and a 6” extension.)

3

Page 30

Phone: 617.527.4385 Fax: 617.964.3746 Email: sales@asrichards.com