Yoshitake OB-4G is a direct acting temperature regulator valve featuring a double-valve structure and an external pressure type bellows, specifically designed for cooling applications. It ensures precise temperature control for cold water, refrigerants, and various non-dangerous fluids while offering distinguished temperature resistance and reliability in industrial cooling systems.

Features

• These temperature regulators do not require any adjusting tool because they are equipped with an adjusting handle which leads to easy adjustment.
• Since these temperature regulators adopt a dual-valve structure, the flow rate is larger than that of single-valve temperature regulators.
• Excellent accuracy since special packing is used for spindle gland packing which affects the opening/closing operation of the valve.
• OB-4G ensures distinguished temperature resistance due to an external pressure type bellows.

Specifications

Model	OB-4G
Application	Cooling
Applied Fluid	Cold water, Refrigerant
Heated Fluid	Cold and hot water, Oil, Non-dangerous fluid
Max. Pressure (Body)	15A-40A: 0.7 MPa [1.0 MPa] 50A, 65A: 0.5 MPa [0.7 MPa] 80A: 0.4 MPa [0.5 MPa] 100A: 0.4 MPa 125A: 0.2 MPa
Max. Pressure (Thermal valve)	1.0 MPa
Maximum Temperature	180°C
Temperature Adjusting Range	For liquid: 15-100°C For air: 15-100°C
Ambient Temperature	Set temp. +30°C or less
Body Material	Cast iron
Valve, Valve Seat Material	Bronze (Stainless steel)
Valve Spindle Material	Stainless steel
Bellows Material	Phosphor bronze
Thermal Valve Material	For liquid: Stainless steel For air: Stainless steel with fin
Standard Capillary Length	15A-80A: 2 m 100A-125A: 3 m
Connection	JIS 10K FF flanged

Notes

• Valve seat leakage is measured under the condition of 0.5 MPa or max. pressure at the temperature of "set temperature - 5°C" for cooling.
• Available with a capillary of up to 5 meters.
• Available with max pressure inside [] (Valve and valve seat material, and bellows is different from standard type).
• Available with thermal well (SUS304 made or with a PTFE cap) for liquid.

Temperature Adjusting Range & Accuracy

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

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

Temperature Accuracy from Set Point:

• Standard capillary (2m): ± 3.5°C
• 2-3.5m capillary: ± 4.0°C
• 3.5-5m capillary: ± 4.5°C (Note: If the preset temperature is higher than 100°C, add ± 1.0°C.)

Cv Value & Valve Seat Leakage

Nominal Size	15A	20A	25A	32A	40A	50A	65A	80A	100A	125A
Cv Value	2	2	4	7	10	14	21	27	42	72
Seat Leakage (L/h, water)	1.5	1.5	1.8	2.4	3.0	3.6	4.8	6.0	7.2	9.0

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

Nominal Size Selection Chart (For Water)

When selecting the nominal size of a temperature regulator whose inlet pressure (P1), outlet (P2), and flow rate are 0.3 MPa, 0.15 MPa, 9 m³/h, respectively, first find the intersection point (a) with the differential pressure (0.15 MPa) before and after valve and the flow rate 9 m³/h. Since this intersection point (a) locates between nominal sizes 32A and 40A, select the larger one, 40A.

Installation & Maintenance

Installation Cautions

• Install the temperature regulator valve vertically against the horizontal pipe, placing its frame above.
• Make sure to install a strainer (60 to 80 mesh) on the inlet side of the product.
• Install pressure gauges on the inlet and outlet sides of the product to confirm the operation.
• Install the thermal bulb in a way that makes three fourths or more of its total length come into contact with the fluid to be heated.
• The bending radius of the capillary tube must be 40 mm or more. Do not bend it at an acute angle.

Thermal Bulb Installation Example

Piping Example

Warnings for Use

• In case of high temperature fluid, do not touch the product directly with bare hands to avoid scalds.
• Do not disassemble the bellows when the thermal bulb is heated. The bellows may be damaged, disrupting the original functions of the product.
• When supplying air or water to the product, make sure to close the stop valves at the front and the rear of the product and remove foreign substances completely through the bypass pipe.