Yoshitake 150L-13S is a plain type sight glass in cast stainless steel (SCS13), designed to permit visual checking of fluid flow inside a pipe. It features a JIS Rc screwed connection and hardened glass, making it suitable for cold and hot water, oil, and other non-dangerous fluids. This model supports a maximum working pressure of 1.0 MPa and temperatures up to 150℃.
Features
- Two component fluid can be checked by its color or mixed state.
- Intermittent fluid flow can be checked.
- Can be connected to either horizontal or vertical piping.
- Available with mica plate for steam condensate (maximum allowable working pressure is 0.6 MPa).
- Body material is cast stainless steel for wider applications.
Specifications
| Specification | Value |
|---|
| Model | 150L-13S |
| Type | Plain |
| Application | Cold and hot water, Oil, Other non-dangerous fluids |
| Nominal size | 15A–50A |
| Maximum working pressure | 1.0 MPa |
| Temperature range | 5–150℃ (Max. temperature: 150℃) |
| Max. thermal shock | 100℃ |
| Connection | JIS Rc screwed |
| Body Material | Cast stainless steel (SCS13) |
| Glass Material | Hardened glass |
WARNING
When applied to steam condensate, use the product with mica plates (model number: 150LM), within max. working pressure of 0.6 MPa and max. temperature of 150℃.
Dimensions and Weights

| Size | d | L | A | B | W | Weight (kg) |
|---|
| 15A | Rc 1/2 | 76 | 73.5 | 51 | 35 | 0.73 |
| 20A | Rc 3/4 | 89 | 73.5 | 51 | 35 | 0.82 |
| 25A | Rc 1 | 114 | 89.0 | 67 | 44 | 1.5 |
| 32A | Rc 1-1/4 | 127 | 114.0 | 80 | 53 | 2.3 |
| 40A | Rc 1-1/2 | 140 | 115.5 | 86 | 57 | 2.9 |
| 50A | Rc 2 | 162 | 147.0 | 114 | 73 | 5.8 |
(Note: The products with protective wire mesh have dimensions A and weights different from the above.)
Parts List
| No. | Name of Parts | Material | Q.TY |
|---|
| 1 | Body | Cast Stainless Steel (SCS13) | 1 |
| 2 | Cover | Cast Stainless Steel (SCS13) | 2 |
| 3 | Glass | Tempered Glasses | 2 |
| 4 | Gasket | Non-Asbestos | 2 |
| 6 | Bolt | Stainless Steel (SUS) | 4 |
| 7 | Nut | Stainless Steel (SUS) | 4 |
| 8 | Gasket | Non-Asbestos | 2 |
Installation and Operation
Precaution for Installation
- Before connecting the product to piping, confirm that the product specifications are sufficient for the service condition.
- Before connecting the product to piping, remove foreign substances and dirt inside the piping. Failure to do so may damage the glass or cause opacity due to scale/oil stains.
- Check the direction of the product so that the fluid flowing and the arrow marked on the product are in the same direction.
- For steam condensate application, make sure to use the product with mica plates to protect the glasses.
- Do not apply excessive load, torque, or vibration to the product.
- Do not excessively screw in the product to the piping.
Precaution for Operation
DANGER
- Do not apply a rapid temperature change to the product during both initial and usual operations. A rapid temperature change may damage the glass resulting in a blowout of the fluid.
- When the product is used for hot fluid, do not touch the product with bare hands.
TIP
- 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.
- The glasses may become opaque after contacting a certain type of fluid. If the glasses become opaque, replace them.
Troubleshooting
| Trouble | Cause | Remedy |
|---|
| Fluid flow cannot be observed. | 1. Foreign substances stick to the inner surface of the glass, or the inner surface of the glass has erosion or scratches. | Disassemble and clean the product to remove foreign substances, or replace the glass. |
| Outside leakage | 1. The gasket leaks. 2. The glass is damaged. | Disassemble the product and replace the gasket or glass. |
Disassembly and Reassembly
Disassembly (150L, 150LM)
- 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.
- Remove the bolts and nuts.
- Take out the covers and glasses. If the glass sticks to the body and hardly comes off, put the cover on the glass in a way that the outer circumference of the glass fits the inner circumference of the cover, and then tap the cover on its outer side.
Reassembly (150L)
- Clean the gasket spaces of the body, covers, and glasses.
- Attach the gaskets, glasses, and gaskets in this order to the covers and assemble them to the body.
- To fix the covers to the body, firstly tighten them temporarily with bolts and nuts, and then tighten them evenly at the specified torque by using a torque wrench.
Tightening Torque:
- 15A, 20A: 7 N·m
- 25A, 32A: 10 N·m
- 40A: 15 N·m
- 50A: 25 N·m
(For 150LM, attach the gaskets, glasses, mica plates, and gaskets in this order to the covers.)