​What is the Difference between an OPD Valve and a POL Valve?

Propane tanks are widely used for various applications, ranging from grilling to heating. Within the world of propane tanks, two types of valves stand out: OPD (Overfill Prevention Device) valves and POL (Prest-O-Lite) valves. These valves serve distinct purposes and come with unique design, functionality, and safety features. In this article, we will delve into the key differences between OPD and POL valves to help you better understand their characteristics and choose the right valve for your needs.

Introduction to OPD and POL Valves: Understanding the Basics

OPD Valve: The Overfill Prevention Device (OPD) valve is a safety mechanism designed to prevent propane cylinders from being overfilled. This valve is required by law in many regions and has become a standard feature on most new propane cylinders. The OPD valve ensures that there is enough space for propane to expand within the cylinder, reducing the risk of leaks and accidents.

POL Valve: The Prest-O-Lite (POL) valve is an older type of valve used in propane cylinders. It is characterized by its left-hand threaded connection and is commonly found on older propane tanks and larger cylinders used in RVs and industrial applications.

Comparing the Design and Structure of OPD and POL Valves

OPD Valve Design: OPD valves are typically equipped with a triangular handwheel that distinguishes them from other valve types. This handwheel is used to open and

close the valve, allowing propane to flow into appliances when needed.
POL Valve Design: POL valves have a distinctive acme thread and a left-hand threading mechanism. They require a wrench to connect and disconnect from the propane

cylinder.

Operational Differences: How OPD and POL Valves Function

OPD Valve Operation: The OPD valve operates by using a float inside the cylinder. As the propane level rises and the cylinder reaches its safe fill level, the float rises and triggers the valve to close, preventing further propane from entering the cylinder.

POL Valve Operation: POL valves are manually operated using a wrench. To open the valve, you turn it clockwise. To close the valve, you turn it counterclockwise. There are no automatic safety mechanisms to prevent overfilling.

Safety Aspects: Evaluating the Safety Features of OPD and POL Valves

OPD Valve Safety Features: The primary safety feature of the OPD valve is its ability

to prevent overfilling, which reduces the risk of leaks and potential hazards. The automatic shutoff mechanism offers peace of mind to users.
POL Valve Safety Features: POL valves lack an automatic shutoff mechanism for overfill prevention. Users must rely on their own vigilance and knowledge of cylinder

capacity to prevent overfilling.

Making a Choice: Factors to Consider when Selecting Between OPD and POL Valves

When deciding between an OPD valve and a POL valve, several factors come into play:
Regulations: Check local regulations to see if OPD valves are required for new cylinders.

Safety: OPD valves offer enhanced safety features compared to POL valves, making them a better choice for preventing overfilling.

Appliance Compatibility: Ensure that the chosen valve type is compatible with your appliances and equipment.

Ease of Use: OPD valves are easier to operate, making them a convenient choice for everyday users.

In conclusion, the choice between an OPD valve and a POL valve depends on safety requirements, regulations, and personal preferences. OPD valves provide automatic overfill prevention and are suitable for most residential applications, while POL valves are often found in larger cylinders for specific industrial purposes. Understanding the differences between these valve types empowers users to make informed decisions that prioritize safety and efficiency.