Armstrong OB-2000 series is a high-performance externally piloted temperature regulator for large capacity applications such as heat exchangers, steam coils, steam dryers, plating tanks, and parts washers. It is self-actuated and requires no external energy source. Capillary units mount in any position and can be easily disconnected and interchanged, offering easy installation and maximum application flexibility. The series is available in sizes 1/2" through 6" with six temperature ranges and three capillary lengths.

Product Variants

OB-2000 Temperature Regulator

Designed for standard steam applications.

• Inlet Pressure: 10 - 300 psig (0.69 - 20 bar)
• Reduced Pressure: 7 psig (0.48 bar)

OB-2000L Low Pressure Temperature Regulator

Designed for large capacity and low-pressure steam applications.

• Inlet Pressure: 5 - 15 psig (0.3 - 1 bar)
• Reduced Pressure: 3 psig (0.21 bar)

OB-2000PT Pressure and Temperature Regulator

The OB-2000PT is a diaphragm-operated externally piloted pressure/temperature combination regulator. It is used in applications where maximum pressure should be limited and the temperature of the heated medium is controlled using a single seated main valve.

• Inlet Pressure: 15 - 300 psig (1 - 20 bar)
• Minimum Differential Pressure: 7 psig (0.48 bar)

Specifications

Sensor and Accessory Specifications

Component	Specification
Capillary Material	Copper Capillary Tube With 304 Stainless Steel Armor Shield
Capillary Temperature Ranges	18-59°F (-8-15°C), 50-97°F (10-36°C), 86-144°F (30-62°C), 131-201°F (55-94°C), 176-260°F (80-127°C), 239-361°F (115-183°C)
Temperature Accuracy	±2°F (±1°C) From Set Point
Capillary Lengths	6-1/2 ft (2m) standard, 9-1/2 ft (3m), 16-1/2 ft (5m)
Bulb Material	Nickel Plated Copper Bulb
Bulb Connection	3/4" (20 mm) NPT
Thermal Well Material	Brass (Standard) or 304 Stainless Steel
Thermal Well Connection	1" (25 mm) NPT

WARNING

Capillary can withstand a maximum of 36°F (20°C) above rated range. If desired set temperature is in temperature range overlap, select lower range.

Materials

Component	Material
Main Valve Body	Ductile Iron ASTM A536
Seat Type & Material	Single Seat Stainless Steel AISI 420
Valve Material	Stainless Steel AISI 420
Temperature Pilot Valve	Bronze ASTM B584
Pressure Pilot (OB-2000PT)	Ductile Iron ASTM A536

Dimensions and Weights

OB-2000 Dimensions

OB-2000L Dimensions

OB-2000PT Dimensions

Installation Guidelines

Points to Remember When Installing:

• Drain condensate at inlet of pressure/temperature regulator with inverted bucket steam trap.
• Protect temperature regulating valve from dirt and scale by installing strainer with 100 mesh screen at inlet of valve.
• Install shutoff valves on either side of the regulating valve along with a by-pass line for maintenance purposes.
• Install vacuum breaker after the outlet of equipment and before the steam trap.
• Install sensor so it is fully immersed in the fluid being heated.
• If temperature well is used, apply heat transfer medium to sensor before insertion into well.
• Place thermometer into system in close proximity to temperature sensor for accurate valve adjustment.
• If possible, do not elevate condensate after steam trap.
• Determine pressure setting before temperature setting (OB-2000PT only).

Maintenance and Disassembly

DANGER

Equipment under pressure - Operating temperature > 100°C. Make sure temperature regulator is cold and all internal pressure has been relieved before handling or disassembly!

Troubleshooting Guide

Problem	Cause	Solution
Temperature regulator does not reach desired set temperature.	Improper adjustment.	Readjust according to Regulating Methods.
	Faulty steam trap draining equipment.	Check trap and correct problem.
	Inadequate pressure to eliminate condensate.	Re-pipe system to gravity drain condensate. Clean Y strainer on inlet to valve.
	Main valve diaphragms are ruptured.	Replace main valve diaphragms.
	No transfer medium applied to thermal bulb.	Apply heat transfer paste to thermal bulb before installation in well.
Temperature rises excessively.	Dirt or scale on main valve and main valve seat or flawed valve and seat.	Disassemble and clean valve and seat. In case of flawed valve and seat - replace.
	Dirt or scale on pilot valve, pilot valve and seat.	Disassemble pilot and clean. Replace if damaged.
	Broken capillary system.	Replace capillary system.
	Bypass line leaks.	Repair bypass.
Large variation between thermometer and temperature regulator setting.	Thermal bulb or thermometer are installed in wrong location.	Relocate thermal bulb in path of fluid so at least 3/4 of bulb is submerged in fluid and/or relocate thermometer closer to thermal bulb.
	Inlet pressure too high.	Lower inlet pressure. On low load applications, the lower the inlet pressure, the more stable the control will be.