Views: 0 Author: J-VALVES Publish Time: 2026-10-14 Origin: Site
“2 inch” normally refers to the nominal pipe size, commonly written as NPS 2. It describes part of the piping and flow-path specification. It does not indicate the number of valves shown in the picture, nor does it replace the actual flange dimensions, bore, face-to-face length or bolt-hole details. Those dimensions must be confirmed from the applicable standard and the product drawing.
“Class 300” belongs to the ASME pressure-class system. It is not a standalone fixed working-pressure value that can be applied without considering temperature, material and valve construction. The permitted pressure-temperature combination must be checked against the applicable standard, material group, operating temperature and the limiting component of the valve. For technical pages, “ASME Class 300” is clearer than treating “300LB” as a pressure value.
A gate valve is normally selected for positive isolation in the fully open or fully closed position. Unless the manufacturer specifically evaluates the service, a standard gate valve should not be presented as a continuous throttling valve.
UNS C95800 is an aluminum bronze casting alloy. The official abstract for ASTM B148-24, Standard Specification for Aluminum-Bronze Sand Castings, lists C95800 among the copper-base alloys covered by the specification and addresses requirements such as chemical composition, mechanical properties and hardness.
That information explains the material designation, but it does not by itself establish the complete valve’s pressure-temperature rating, sealing performance, maximum service temperature or certification status. The valve body, bonnet, stem, wedge, seats, gaskets, packing and fasteners should be identified separately in the material schedule or purchase documents.
Aluminum bronze should not be described as suitable for every corrosive medium. Chlorides, abrasive particles, chemical additives, ammonia, acids, alkalis, concentration, velocity and temperature may all affect material compatibility. The correct selection must be based on the actual medium and the complete sealing system.
The photo shows several similar flanged gate valves with bolted bonnets, yoke-type rising-stem arrangements and metallic bronze-colored bodies. These visible features are useful for explaining the product form and workshop context. They do not reliably prove the flange standard, pressure class, material certificate, leakage class or customer-project approval.
If a product page uses “Class 300,” “C95800,” API or ASME compliance claims, those statements should be supported by traceable technical documents. A photograph should not be used as the only evidence for a pressure rating, certificate or test result.
The official ASME page for B16.34-2025 states that the standard covers pressure-temperature ratings, dimensions, tolerances, materials, nondestructive examination requirements, testing and marking for a range of flanged, threaded, welding-end and certain wafer or flangeless valves. In an actual project, the specified edition and related piping and flange standards must be confirmed.
Before ordering, request confirmation of:
Nominal size, end connection and face-to-face dimension;
Flange standard, facing, drilling and connection class;
Body, bonnet and other pressure-retaining material grades;
Design pressure, operating pressure, design temperature, operating temperature and medium;
Seat, packing, gasket and stem-sealing materials;
Shell test, seat test and acceptance requirements.
This approach prevents the common mistake of converting “Class 300” into a fixed pressure number without checking the actual conditions.
In a machining shop, a gate valve may be considered for industrial cooling-water lines, equipment utility water, general process-water isolation and other workshop utility piping. Its main function in these services is to isolate a section of line for maintenance, equipment shutdown or system zoning.
However, “machining shop” is not a complete service specification. The fluid may be clean water, recirculating coolant, a solution containing additives, or a process medium carrying particles. Before selecting the valve, confirm:
Medium composition, concentration, temperature and velocity;
Whether chips, abrasives, oils or chemical additives are present;
Whether the valve is for isolation or frequent operation;
Required shutoff leakage class and test medium;
Available maintenance space for the handwheel and rising stem.
If the line requires continuous flow control, reassess the valve type. Keeping a conventional gate valve partly open for long periods can create vibration, erosion, noise or sealing concerns. A gate valve should not be treated as a control valve simply because it can be positioned somewhere between open and closed.
Item | C95800 aluminum bronze | Carbon steel | Stainless steel |
Material family | Copper-base aluminum bronze alloy | Iron-base carbon steel | Iron-base stainless steel |
Selection focus | Alloy grade, medium, sealing materials, pressure and temperature | Corrosion allowance, temperature and protective system | Specific grade, chloride exposure and temperature |
Common mistake | Calling it suitable for every corrosive medium | Treating it as a universal water-service material | Writing only “stainless steel” without the grade |
Replacement rule | Do not substitute by color, price or material name alone. Compare the medium, temperature, pressure, flange system and sealing arrangement. | ||
Product datasheet, general arrangement drawing and face-to-face dimension;
Material certificates for the body, bonnet and pressure-retaining parts;
Material list for seats, gaskets, packing and fasteners;
Flange dimensions, facing and drilling information;
Pressure-temperature rating table and design standard;
Shell and seat test records or inspection and test plan;
Project-specific quality documents and certificates, where applicable.
If a supplier provides only a product photograph or the phrase “Class 300 C95800” without supporting documentation, the buyer should not treat the application as fully verified.
It generally indicates NPS 2 nominal size and ASME Class 300 pressure class. Actual flange dimensions, face-to-face length and pressure-temperature ratings must be confirmed from the drawing and applicable standards.
No. Class 300 is a pressure-class designation. The allowable pressure changes with material, temperature, design and the limiting component; it cannot be replaced with a fixed 300 psi statement.
C95800 is a UNS aluminum bronze casting alloy. If ASTM B148 is cited, state that it covers aluminum bronze sand castings and do not imply that it automatically certifies the complete valve.
It may be suitable for selected industrial-water or utility-piping services after the medium, temperature, pressure, operation frequency, sealing materials and test requirements have been reviewed. The photo alone cannot establish suitability.
Gate valves are primarily isolation valves. Continuous throttling requires a specific manufacturer evaluation and may call for a dedicated control valve or another suitable valve design.
No. API 600 is principally associated with steel bolted-bonnet gate valves. If a project specifies API 600, the manufacturer must confirm the current edition, material scope, design and inspection documentation.
Reliable specification of a 2-inch Class 300 C95800 aluminum bronze gate valve is not about repeating the product keyword. It is about connecting nominal size, pressure class, material grade, sealing system, medium, temperature and inspection requirements. The product photograph can help a buyer recognize the visible construction, but it cannot replace the drawing, material certificate or test documentation.
For a machining-shop application, include the medium, operating temperature, design pressure, connection standard, operating frequency and acceptance requirements in the inquiry. This gives the supplier enough information to confirm the configuration instead of relying on the short description “2 300LB C95800 gate valve.”
