Yoshitake OB-1 and OB-1G are direct-acting temperature regulators designed for heating applications. Featuring a double valve structure, these regulators offer a larger flow rate than single valve types. The OB-1 series utilizes a bellows mechanism and is available with a standard 2m capillary, making it suitable for controlling the temperature of cold/hot water, oil, and other non-dangerous fluids using steam or hot water as the heating medium. The OB-1G variant features an external pressure type bellows, ensuring distinguished temperature resistance when ambient temperatures are higher.

Features

• Easy plumbing due to union type connection screw.
• No need for adjusting tool due to the attached adjusting handle, making adjustment easy.
• Double valve structure offers larger flow rate than single valve type.
• Excellent accuracy since special packing is used for spindle gland packing which affects opening/closing operation of the valve.
• The OB-1G ensures distinguished temperature resistance due to external pressure type bellows.

Specifications

Model	OB-1	OB-1G
Application	Heating	Heating
Heating Fluid	Steam, Hot water	Steam, Hot water
Heated Fluid	Cold and hot water, Oil, Non-dangerous fluids	Cold and hot water, Oil, Non-dangerous fluids
Maximum Pressure (Body)	0.7 MPa	0.7 MPa
Maximum Pressure (Thermal bulb)	1.0 MPa	1.0 MPa
Max. Temperature	180°C	180°C
Temperature Adjusting Range (For liquid)	40-120°C	15-100°C
Temperature Adjusting Range (For air)	40-120°C	15-100°C
Ambient Temperature	Set temperature -10°C or less	Set temperature +30°C or less
Body Material	Cast bronze	Cast bronze
Valve Material	Bronze	Bronze
Valve Spindle Material	Stainless steel	Stainless steel
Bellows Material	Phosphor bronze	Phosphor bronze
Thermal Bulb Material	Stainless steel	Stainless steel
Standard Capillary Length	2m	2m
Connection	JIS Rc screwed (union joint)	JIS Rc screwed (union joint)

Notes

• Valve seat leakage: Refer to P.I3-39 (in original catalog).
• If the ambient temperature is higher than the set temperature or less than 40°C, use the OB-1G (with external pressure type bellows).
• Available with capillary of up to 5 meter.
• Available with temperature adjusting range of 30°C (For OB-1 only).
• Available with thermal well (SUS304 made or with a PTFE cap) for liquid.

Temperature Adjusting Range

OB-1

Temperature Adjusting Range (°C) For Liquid	Temperature Adjusting Range (°C) For Air	Withstand Temperature (°C)
40-60	40-60	70
50-70	50-70	80
60-80	60-80	90
80-100	80-100	110
100-120	100-120	130

The term "withstand temperature" means the temperature from pressure resistance of the bellows.

OB-1G

Temperature Adjusting Range (°C) For Liquid	Temperature Adjusting Range (°C) For Air	Withstand Temperature (°C)
15-35	15-35	50
20-40	20-40	50
35-55	35-55	70
40-60	40-60	90
50-70	50-70	100
60-80	60-80	110
70-90	70-90	120
80-100	80-100	130

The term "withstand temperature" means the temperature from pressure resistance of the bellows.

Dimensions and Weights

Nominal Size	d	L	H1	H	Weight (kg)
15A	Rc 1/2	148	55	510	11
20A	Rc 3/4	148	55	510	11
25A	Rc 1	160	60	520	12
32A	Rc 1-1/4	195	60	520	12
40A	Rc 1-1/2	210	65	530	13

Nominal Size Selection Chart (For Steam)

How to Use the Chart

When selecting the nominal size of a temperature regulator whose inlet pressure (P1), outlet pressure (P2), and steam flow rate are 0.3 MPa, 0.25 MPa, and 60 kg/h, respectively, first find intersection point (a) of the inlet pressure of 0.3 MPa and the outlet pressure of 0.25 MPa. Trace down vertically from this intersection point (a) to find intersection point (b) with the flow rate of 60 kg/h. Since this intersection point (b) lies between nominal sizes 15A or 20A and 25A, select the larger one, 25A.

Structural Drawings

No.	Part Name	Material
39	Fin	Stainless Steel (SUS304)
38	Gasket	Non-Asbestos
37	Bolt	Steel
36	Cap	Stainless Steel (SUS304)
35	Thermal Element Flange	Cast Stainless Steel (SCS13)
34	Screw Flange	Cast Stainless Steel (SCS13)
33	Thermal Element Pipe	Stainless Steel (SUS304)
32	Flexible	Stainless Steel (SUS304)
31	Flexible Tube	Copper Tube (C1220)