Yoshitake OB-2 and OB-2G are direct-acting temperature regulators designed for heating applications. Featuring a double-valve structure, these regulators offer a larger flow rate compared to single-valve types and utilize a specialized spindle gland packing to ensure high accuracy in opening and closing operations. The standard OB-2 utilizes a phosphor bronze bellows, while the OB-2G incorporates an external pressure-type bellows to provide distinguished temperature resistance, making it suitable for varying ambient conditions.

Features

1. No need for an adjusting tool due to the attached adjusting handle, making adjustment easy.
2. Double valve structure offers a larger flow rate than the single valve type.
3. Excellent accuracy since special packing is used for the spindle gland packing, which affects the opening/closing operation of the valve.
4. The OB-2G ensures distinguished temperature resistance due to an external pressure-type bellows.

Specifications

Specification	OB-2	OB-2G
Application (Heating fluid)	Steam, Hot water	Steam, Hot water
Application (Heated fluid)	Cold and hot water, Oil, Non-dangerous fluids	Cold and hot water, Oil, Non-dangerous fluids
Maximum Pressure (Body)	15A-40A: 0.7 MPa [1.0 MPa] 50A-65A: 0.5 MPa [0.7 MPa] 80A-100A: 0.4 MPa [80A: 0.5 MPa] 125A: 0.2 MPa [0.35 MPa for OB-2] 150A: 0.2 MPa	15A-40A: 0.7 MPa [1.0 MPa] 50A-65A: 0.5 MPa [0.7 MPa] 80A-100A: 0.4 MPa [80A: 0.5 MPa] 125A: 0.2 MPa
Maximum Pressure (Thermal bulb)	1.0 MPa	1.0 MPa
Maximum Temperature	180°C	180°C
Temperature Adjusting Range	For liquid/air: 40-120°C	For liquid/air: 15-100°C
Ambient Temperature	Set temperature -10°C or less	Set temperature +30°C or less
Standard Capillary Length	15A-80A: 2 m 100A-150A: 3 m	15A-80A: 2 m 100A-125A: 3 m
Connection	JIS 10K FF flanged	JIS 10K FF flanged

Materials

• Body: Cast Iron
• Valve, valve seat: Bronze (stainless steel)
• Valve spindle: Stainless steel
• Bellows: Phosphor Bronze
• Thermal bulb: Stainless steel

Application Notes

• Valve seat leakage: Refer to manufacturer standards.
• If the ambient temperature is higher than the set temperature or less than 40°C, use the OB-2G (with external pressure type bellows).
• If using at a pressure higher than 0.5 MPa, stainless steel trim parts are recommended.
• Available with capillary of up to 5 meters.
• Available with max pressure inside []. (Valve and valve seat material, and bellows are different from standard type).
• Available with temperature adjusting range of 30°C (For OB-2 only).
• Available with thermal well (SUS304 made or with a PTFE cap) for liquid.

Temperature Adjusting Range

OB-2

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

OB-2G

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

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

Dimensions and Weights

Nominal Size	L (mm)	H1 (mm)	H (mm)	Weight (kg)
15A	126	60	520	15
20A	130	60	520	16
25A	140	70	540	18
32A	150	75	550	21
40A	160	75	550	23
50A	180	110	620	29
65A	215	125	650	38
80A	260	135	670	48
100A	300	160	750	58
125A	360	190	810	76
150A	382	220	980	125

Note: The OB-2G comes in nominal size up to 125A. Dimensional drawings for larger sizes may vary slightly.

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.

Note: Chart of the flow rate is a reference value.

Structural Drawings

15A-40A Sizes

No.	Name of Parts	Material
1	Body	Cast Iron (FC200)
2	Bottom Cover	Brass (C3771)
3	Top Valve Seat	Phosphor Bronze or Bronze
4	Under Valve Seat	Phosphor Bronze or Bronze
5	Valve	Phosphor Bronze or Bronze
10	Gland Packing	PTFE
24	Bellows	Phosphor Bronze (C5212)
31	Flexible Tube	Copper Tube (C1220)
33	Pipe	Stainless Steel (SUS304)