TOYO valve pressure and temperature selection

Specific precautions for ball valves and butterfly valves

5.1 Ball valve

TOYO offers bronze, brass, and stainless steel ball valves with a maximum pressure rating of Class 600 (600WOG). For example:

Brass ball valve 600RC-N (Fig. 5026): CWP (cold working pressure) 4.13 MPa (38 ℃), test pressure 6.20 MPa. Suitable for water, oil, and gas, but prohibited for steam (unless specially designed).

Stainless steel ball valve UZ-N (Fig. 3550): also Class 600, but with SCS14A body and PTFE seat, suitable for corrosive fluids.

Selection note: PTFE valve seats will soften at high temperatures. The specific temperature pressure curve is not provided in the catalog, and it is generally recommended to be ≤ 180 ℃. If the temperature exceeds this limit, metal seals or special polymer valve seats should be used.

5.2 Butterfly valve

Butterfly valves (aluminum bronze disc, EPDM/NBR seat) are suitable for high flow and low pressure conditions. The restrictions are given on page 26 of the table of contents:

NBR valve seat is not suitable for hot water systems (early aging).

EPDM valve seats shall not be used for any oily media.

When using JIS 5K flange, the maximum allowable working pressure is limited by the flange (static water 0.7 MPa, pulsation 0.6 MPa).

Special working conditions and product limitations

6.1 Non Asbestos Fillers

TOYO catalog page 32 states: The standard packing and gasket for bronze, brass, and cast iron valves have been made of asbestos free materials, which meet environmental requirements. If you need other materials (such as flexible graphite, PTFE), please consult specifically.

6.2 Prohibited Use Scope

Multiple pages repeatedly emphasize that TOYO conventional valves are strictly prohibited from being used for flammable or toxic gases (such as natural gas, hydrogen, chlorine, etc.). Special valves that comply with high-pressure gas safety laws must be used.

6.3 Temperature Limits for Welded End Valves

For stainless steel valves with welded ends, pressure temperature ratings above 1000 ° F (538 ℃) are still valid, but for flange end valves, the maximum is 1000 ° F. If the temperature exceeds 450 ℃, the manufacturer should be consulted.

Selection Decision Process (Practical Steps for Engineers)

Determine whether the medium is water, oil, gas, or steam? Is it corrosive? Is it flammable/toxic? If flammable/toxic, exclude standard products directly.

Check working temperature: Find the allowable pressure for each candidate material (bronze, cast iron, ductile iron, stainless steel) at that temperature.

Comparison of work pressure: The allowable pressure must be selected to be greater than or equal to the maximum working pressure of the system (including water hammer pressure).

Choose connection method: thread, flange, welding, clamp. Flange valves should pay attention to the pressure rating of the flange (such as JIS 5K flange limit butterfly valve pressure).

Special functions: whether adjustment type (globe valve), quick switch (ball/butterfly valve), check function (check valve), filtration (Y-shaped filter) are required.

Verification: Ensure installation space by comparing the dimensions (L, H, D) in the directory.

Common errors and troubleshooting

Possible causes and solutions for error phenomena

Bronze gate valves are used for leakage and overheating under steam at 150 ℃. When gaskets/packing aging, Class 300 or cast iron valves are used instead, and the steam rated pressure (0.86 MPa) is checked

Butterfly valve EPDM seat incompatible with expansion medium and rubber in oil system, switch to NBR seat or replace with stainless steel ball valve

Stainless steel ball valve experiences a significant increase in torque at high temperatures, while PTFE valve seat softens and deforms to reduce temperature, or a metal sealed ball valve can be used instead

Cracks in cast iron valve body (winter), increased heat tracing or drainage due to medium freezing and expansion, or use ductile iron instead

Maintenance and spare parts recommendations

Gaskets and Fillers: Non asbestos gaskets are used for cast iron valves in the catalog, and spare parts should be made of the same material to avoid mixing asbestos containing products.

Filter cleaning: The standard mesh size for Y-shaped filters (such as 150-BT-N) is 12-16 mesh, and finer or coarser filters can be customized according to needs.

Regular pressure testing: On site pressure testing should refer to the "test pressure" (shell water, seal air) in the catalog, such as Class 125 bronze valve shell test 2.06 MPa.