If you've ever shopped for a ball valve, you've probably noticed numbers and letters stamped on the valve body, such as 600 WOG, 600 CWP, or 150 WSP.
But what do those markings actually mean? And how do you know which ball valve is right for your plumbing project?
Whether you're a professional plumber, contractor, or DIY homeowner, understanding these ratings can help you choose the right valve for the job. Here's what you need to know.
What Does 600 WOG Mean?
600 WOG means a valve has a pressure rating of 600 pounds per square inch (PSI) under specified non-shock, ambient-temperature conditions.
WOG stands for:
- W: Water
- O: Oil
- G: Gas
The term is a traditional way of identifying a valve's cold-service pressure rating. For example, a brass ball valve marked 600 WOG is rated for up to 600 PSI under the conditions specified by the manufacturer.
However, that doesn't mean the valve can safely handle 600 PSI at every temperature or with every type of fluid. Temperature, material compatibility, and the manufacturer's specifications all play an important role.
Important: The word “gas” in WOG does not automatically mean the valve is approved for natural gas, propane, or other combustible gases. Those applications require appropriate product approvals and specifications.
600 WOG vs. 600 CWP: What's the Difference?
You may also see ball valves labeled 600 CWP instead of 600 WOG. CWP stands for Cold Working Pressure.
Both markings describe pressure ratings, but CWP is the more modern and preferred designation under industry valve-marking standards.
| Rating | Meaning |
|---|---|
| 600 WOG | 600 PSI non-shock pressure rating under specified ambient conditions |
| 600 CWP | 600 PSI cold working pressure |
| 150 WSP | 150 PSI working steam pressure, when specified by the manufacturer |
CWP ratings generally reference a cold-temperature range of approximately -20°F to 100°F, although applicable manufacturer specifications should always be checked.
A valve's steam rating may be significantly lower than its WOG rating. For example, certain brass ball valves are rated 600 PSI WOG and 150 PSI WSP. That is why it's important to check the complete product specifications rather than relying on one number.
What Is a 600 WOG Ball Valve Used For?
A 600 WOG ball valve is commonly found in plumbing, mechanical, and industrial systems where quick, reliable shutoff is needed.
Depending on the valve's construction and approvals, applications may include:
- Residential and commercial water supply lines
- Plumbing shutoff and isolation points
- Heating and HVAC systems
- Compressed air systems
- Certain compatible industrial fluid systems
Ball valves are especially useful because they operate with a simple quarter-turn handle. Turn the handle 90 degrees to open or close the valve. On typical lever-operated ball valves, the handle is parallel to the pipe when open and perpendicular when closed.
For plumbers and contractors, this makes ball valves a practical choice for systems that require convenient shutoff access.
Full-Port vs. Standard-Port Ball Valves
Another important consideration when choosing a ball valve is whether you need a full-port or standard-port design.
Full-Port Ball Valves
A full-port ball valve has an opening through the ball that is approximately the same diameter as the connecting pipe's internal flow passage. This design helps minimize flow restriction and pressure loss. Full-port valves are commonly selected when maintaining flow capacity is important.
Standard-Port Ball Valves
A standard-port ball valve has a smaller opening through the ball. This creates more flow restriction than a comparable full-port design, but it may be suitable for applications where maximum flow is not necessary.
Which Should You Choose?
If minimizing flow restriction is a priority, a full-port ball valve is often the better option.
Fittings N' Valves carries a range of full-port threaded ball valves for residential, commercial, and professional plumbing applications.
How to Choose the Right 600 WOG Ball Valve
A pressure rating is only one part of choosing the correct valve. Before placing an order, consider these five factors.
1. Pressure Rating
Confirm that the valve's working pressure rating meets the requirements of your system, including operating temperature and pressure conditions. A 600 WOG marking alone does not establish suitability for every application.
2. Valve Size
Choose a valve that matches the required nominal pipe and connection size. Common threaded ball valve sizes include 1/2 inch, 3/4 inch, and 1 inch.
Fittings N' Valves offers several 600 WOG brass ball valve options, including:
- 1/2-inch Brass Ball Valve: 600 WOG, Full Port, Lead-Free
- 3/4-inch Brass Ball Valve: 600 WOG, Full Port, Lead-Free
- 1-inch Brass Ball Valve: 600 WOG, Full Port, Lead-Free
3. Material
Brass and stainless steel are common materials used in ball valves. Brass is widely used in residential and commercial plumbing, while stainless steel may be preferred for certain demanding environments or fluid-compatibility requirements.
For drinking-water applications, verify that the specific valve meets applicable lead-content requirements and approvals.
4. Connection Type
Not every ball valve connects to piping the same way. Common options include threaded NPT connections, solder or sweat connections, PEX connections, and press connections.
Make sure the valve's connection type is compatible with your existing piping and installation method.
5. Application and Approvals
Before installation, check the valve's temperature range, material compatibility, pressure rating, and required certifications. This is particularly important for combustible gas, steam, and other specialized systems.
Frequently Asked Questions About 600 WOG Ball Valves
Does 600 WOG Mean 600 PSI?
Yes. A 600 WOG marking indicates a 600 PSI pressure rating under the manufacturer's specified non-shock, ambient-temperature conditions. It does not mean the valve is rated for 600 PSI at all temperatures.
Is a 600 WOG Ball Valve Good for Plumbing?
A properly selected 600 WOG ball valve can be an excellent choice for many plumbing applications. The correct size, connection type, material, and applicable approvals are just as important as the pressure rating.
Can a 600 WOG Ball Valve Be Used for Natural Gas?
Not based on the WOG marking alone. A valve intended for natural gas or propane must have the required approvals and be rated for that specific service.
What Does 150 WSP Mean on a Ball Valve?
WSP stands for Working Steam Pressure. A valve marked 150 WSP has a manufacturer-specified steam pressure rating of 150 PSI under applicable conditions. Always check the full steam-service specifications.
Is a Full-Port Ball Valve Better Than a Standard-Port Ball Valve?
Full-port valves provide a larger flow opening and generally create less flow restriction. Standard-port valves may be suitable when that additional flow capacity is unnecessary. The best option depends on your system requirements.
Can I Use a 600 WOG Ball Valve for Drinking Water?
Only if the specific valve is approved for potable-water use and meets applicable requirements. Look for relevant certifications, such as NSF/ANSI/CAN 61 and NSF/ANSI 372, as appropriate.
Shop 600 WOG Ball Valves at Fittings N' Valves
Finding the right ball valve shouldn't be complicated.
At Fittings N' Valves, we carry a wide selection of brass, stainless steel, threaded, PEX, and other ball valves for professional contractors, plumbers, and DIY customers.
Whether you're replacing a shutoff valve or sourcing materials for a larger project, you can compare products, sizes, and connection types in one place.
Buying for your business? Our TradePRO program offers wholesale pricing, a dedicated advisor, and convenient ordering benefits for professional customers.
Have a question about selecting the right valve? Contact Fittings N' Valves at 888-550-6593 for assistance.
