Configuration | Flame Detector Adapters
"R" ADAPTERS for FLAME DETECTORS
“R” type adapters are available to fit many different flame detector connection sizes. They have a quartz sealing window and a connector for cooling or purging air. Most adapters have a ¾" NPT thread to fit the ¾" NPT flame detector mounting location on most North American burners. The basic 8835-R unit is common to most “R” adapters. It has a ¾" NPT male connection on both ends. Other adapters are made from the 8835-R by adding the appropriate fitting to one end. A larger adapter is also available with 1" NPT connection as 8833- R. All “R” adapters are rated for up to 10 psig backpressure. To find the right adapter, pick the “detector end” thread that matches the UV detector thread. The adapter can be installed in different configurations to suit the application. The most common is to use air to purge the burner connection side of the quartz sealing lens. This keeps the UV tunnel clear of products of combustion (CO2 and water vapor) which filters UV radiation and makes it harder for the detector to see the flame.
Air connection
Quartz lens
Cooling air
Vent hole open
"UV detector side" cooling air orientation for isolating the purge air when sighting through a fuel passage
This alternate configuration uses approximately 1 cfm of air (at 8 osig pressure) to cool the adapter as it passes through the space between the quartz sealing lens and the flame detector. This con- figuration is only used when no purge air flow can be tolerated by the burner. “R” Adapters are shipped in the “burner side” purge air orienta- tion with a setscrew plugging the hole that vents purge / cooling air. Leave the setscrew in place for “burner side” purging air. Remove the setscrew and swap the UV fitting side if “detector side” cooling air is employed.
Air connection Quartz lens
Purge air
Some adapters are available pre-assembled in the alternate con- figuration as -RA adapters (for example 8836-RA).
Vent hole closed
ADAPTERS and DETECTORS
"Burner side" purge air orientation for purging an UV sight tunnel
Adapter Connection Thread Size*
Approximately 2 to 3 cfm of air is enough to keep the fire side of the quartz sealing lens clean and provide cooling to the UV scanner and adapter assembly. In this configuration, the flame detector is isolated from the purging air and burner environment/ combustion chamber by the quartz sealing lens. If the burner develops backpressure and/or when firing into a positive combustion chamber, use sufficient air pressure to assure positive purge air flow through the adapter. Purge air flow can influence the lighting characteristics of certain burners and/or limit their performance range at reduced firing rate. Care must be taken to adjust the purge air flow for adequate purge and cooling without introducing an undesirable limitation in burner ignition reliability or performance. The air connection fitting provided accepts a ¼” tube at the inlet and threads into a 1⁄8 ” NPT connection on the adapter. (the 8833-R has a 3⁄8 " tube and ¼ " NPT connector) If the adapter will be attached to a UV port that is part of the fuel system, the adapter should be configured so that the lens isolates the fuel from the purge/cooling air.
Adapter
Detector End
Burner End
8831-R 8833-R
3⁄8 " MNPT 1" MNPT ¾ " MNPT ½ " MNPT ¾ " FNPT ¾ " MNPT ½ " MNPSM 1" MNPSM
¾ " MNPT 1" MNPT 1" MNPT 1" MNPT ¾ " MNPT ¾ " MNPT ¾ " MNPT ¾ " MNPT ¾ " MNPT
8833-R-0 8833-R-01
8834-R 8835-R 8836-R 8837-R 8839-R
1" MNPT
* shipped in "Burner side" purge air orientation
Adapter Connection Thread Size#
8836-RA Adapter
Detector End
Burner End
½ " MNPSM
¾ " MNPT
# shipped in UV cooling air configuration with set screw still in the vent hole. Remove set screw to "UV detector side" cooling.
Bulletin 8832 Page 9
Made with FlippingBook flipbook maker