The Yoshitake SB-1S is a compact and space-saving ball-type sight glass suitable for cold and hot water applications. It allows users to easily check the flowing state of the fluid through the movement of the synthetic resin balls inside the product. The rolling balls maintain contact with the inner surface of the glass, making it less liable to water scale accumulation. Constructed with a ductile cast iron body and hardened glass, the SB-1S is designed for a maximum working pressure of 1.0 MPa and a maximum temperature of 85°C. It can be installed in both horizontal and vertical piping setups, provided the glass part faces sideways. The related model SB-1F shares similar specifications but features JIS 10K FF flanged connections.

Features

• Fluid flow can be checked by the movement of the balls inside the product.
• Inner surface of the glass is less liable to water scale because the rolling balls contact the surface.
• Compact, lightweight and space saving.
• Can be connected to horizontal/vertical piping (but glass part should face sideways).

Specifications

Model	SB-1S	SB-1F
Application	Cold and hot water	Cold and hot water
Max. working pressure	1.0 MPa	1.0 MPa
Max. temperature	85°C	85°C
Body	Ductile cast iron	Ductile cast iron
Glass	Hardened glass	Hardened glass
Ball	Synthetic resin	Synthetic resin
Connection	JIS Rc screwed	JIS 10K FF flanged

Consumable Parts

The glass part and balls are consumable parts.

• Three colored balls for 15A-25A: Red (1), White (1), Blue (1).
• Three colored balls for 32A-50A: Red (1), White (2).

Dimensions and Weights

SB-1S (JIS Rc screwed)

Nominal size	d	L (mm)	W (mm)	Weight (kg)
15A	Rc 1/2	80	35	0.7
20A	Rc 3/4	90	35	0.8
25A	Rc 1	115	44	1.4
32A	Rc 1-1/4	127	57	2.5
40A	Rc 1-1/2	140	57	2.8
50A	Rc 2	162	73	5.4

SB-1F (JIS 10K FF flanged)

Nominal size	d (mm)	L (mm)	W (mm)	Weight (kg)
15A	15	130	35	2.2
20A	20	130	35	2.6
25A	25	150	44	4.1
32A	32	160	57	5.9
40A	40	170	57	6.2
50A	50	200	73	9.5

Minimum and Maximum Flow Rates

Nominal size	Min. flow rate	Max. flow rate
15A	0.6	1.5
20A	0.7	2.6
25A	0.8	4.3
32A	1.6	7.2
40A	2.0	9.8
50A	2.5	15.8

Flow Rate Note

The min. flow rate means the lowest flow rate required to start moving one or more balls, while the max. flow rate means the flow rate at which the flow velocity reaches 2 m/s. The pressure loss at the max. flow rate is 0.05 MPa.

Installation and Operation

Piping Example (For cold and hot water)

Precautions for Installation

Installation Cautions

1. Before connecting the product to piping, remove foreign substances and dirt inside the piping. Failure to follow this notice may make the glass damaged due to scratches by foreign substances or may make the fluid cannot be seen through the glass due to glass opacity caused by scale stains.
2. When installing, check the direction of the product so that the fluid flowing and the arrow marked on the product are in the same direction. Setting the product in wrong directions prevents the product from functioning properly.
3. Do not apply excessive load, torque or vibration to the product. Failure to follow this notice may result in leakage.
4. When using sealing material to install SB-1S, take care so that the sealing material does not get inside the piping.

Required space for disassembly/removal of the product:

Nominal size	A (mm)	B (mm)
15A-25A	30 or more	100 or more
32A-40A	35 or more	120 or more
50A	40 or more	150 or more

Precautions for Operation

Operational Warnings

1. Before applying the fluid to the product, confirm that the product is connected to the pipes securely. Failure to follow this notice may cause a blowout of the fluid, resulting in scalds or property damage.
2. Do not apply a rapid temperature change to the product during both initial and usual operations. In case of a possible frozen line, take proper measures to remove the fluid inside the piping to avoid freezing. A rapid temperature change or freezing may damage the glass resulting in a blowout of the fluid.
3. Do not retighten the cover of the product. Failure to follow this notice may damage the glass resulting in fluid blowout.

Operational Cautions

1. The balls for SB-1S and SB-1F are consumable parts. When diameters of the balls become 5 mm or less for 15A-25A, or 7 mm or less for 32A-50A, replace the balls.
2. Make sure that the maximum flow rate is 2 m/s. If flow rate is too high, abrasion of the ball is accelerated. Use the product at a flow rate between the min. and max. flow rates.

Troubleshooting

Trouble	Cause	Remedy
Ball does not move	1. The balls are caught by foreign substances sticking to the inner surface of the glass. 2. The balls are caught by scratches on the balls or on the inner surface of the glass. 3. Flow rate does not reach the min. limit. 4. Fluid does not flow. 5. The product is installed in the opposite direction of the fluid flow.	1. Disassemble and clean the product to remove the foreign substances. 2. Disassemble the product and replace the damaged parts. 3. Replace the product with one of a nominal size that ensures a flow rate of the min. limit. 4. Check the piping. 5. Reinstall the product correctly (match the arrow mark with flow direction).
Fluid flow cannot be observed	1. Foreign substances stick to the inner surface of the glass, or the glass is stained. 2. The inner surface of the glass has erosion or scratches. 3. The balls move too fast due to excessively high flow rate.	1. Disassemble and clean the product to remove the foreign substances. 2. Disassemble the product and replace the glass. 3. Keep the flow velocity 2 m/s or less.
Outside leakage	1. The gasket leaks. 2. The glass is damaged. 3. The body is damaged.	1. Disassemble the product and replace the gasket. 2. Disassemble the product and replace the glass. 3. Replace the product with a new one.

Disassembly and Reassembly

Disassembly Warning

Completely discharge the pressure inside of the product, piping and equipment prior to disassembly and inspection. When fluid is hot, cool down the product to the condition that it can be touched with bare hands. Failure to follow this notice may result in scalds or injury due to the residual pressure.

Cleaning and Replacement Cautions

1. Clean the gasket spaces of the body, covers and glasses.
2. The glasses are consumable parts. Replace the glass if it is eroded by more than 10% of its thickness or if it has scratches or flaws.
3. The gaskets are consumable parts. Replace them with new ones at the time of reassembly.
4. When disassembling, put a container under the product to collect fluid flowing out.

Disassembly

1. Completely discharge the pressure inside of the product. Remove the bolts, nuts, and spring washers (for 15A-25A only) using spanners.
2. Take out gaskets, glasses, gaskets and covers. Since the balls can fall out when the glass is detached from the body, be careful not to lose the balls. Take out all the balls.

Reassembly

1. Put the balls into the ball casing, and then attach the gaskets, glasses, gaskets, and covers in this order to the body. Check that the balls are as specified before putting them into the casing.
2. To fix the covers to the body, firstly tighten them temporarily with the bolts, spring washers (for 15A-25A only), and nuts, and then tighten them evenly at the torque specified by using a torque wrench. Overtightening damages the glass.

Tightening torque:

Nominal size	Tightening torque
15A, 20A	7 N·m
25A	10 N·m
32A, 40A	15 N·m
50A	25 N·m