QB2 Exhaust Valve Model Comparison Table: Quick Selection and Parameter Matching Guide

QB2 Exhaust Valve Model Comparison Table: Quick Selection and Parameter Matching Guide 

In piping systems such as water supply and drainage, and centralized heating, gas resistance and negative pressure collapse are common issues that affect the operational efficiency and safety of the pipelines. The QB2 exhaust valve, as a classic double-port exhaust device, with its core capabilities of automatic exhaust and negative pressure replenishment, has become an essential auxiliary component for pipelines. This article will present you with the model comparison table, quick selection techniques, and parameter matching guide for the QB2 exhaust valve, helping you easily select a high-quality QB2 exhaust valve that meets the requirements of the pipeline.

Detailed Explanation of QB2 Exhaust Valve Model Comparison

The QB2 exhaust valve is also known as P2 double-port exhaust valve. The current mainstream models include QB2-10, QB2X, QB2-16, etc. Different models correspond to different pressure ratings and application scenarios:

.QB2-10 model: Nominal pressure PN10, it is the most widely used basic QB2 exhaust valve at present, with a pipe diameter range of DN40 to DN300, suitable for normal temperature clear water and hot water pipelines with a temperature not exceeding 100℃, with exhaust flow rates ranging from 4 to 173 m³/h to 27 to 1145 m³/h, capable of meeting the exhaust requirements of most medium-sized pipe diameters.

.QB2-16 model: Nominal pressure PN16, with a pipe diameter range of DN40 to DN200, suitable for higher pressure pipeline scenarios, applicable to temperature ranges of -29℃ to +80℃, the valve body can be made of cast iron, cast steel, or stainless steel, meeting the exhaust and replenishment requirements under high pressure conditions.

.QB2X double-port exhaust valve: Features a stainless steel float ball configuration, with stronger corrosion resistance, suitable for hot water pipelines with complex water quality, with a shell strength test pressure of up to 1.5 MPa, and the float ball sealing test pressure covers 0.05 to 1.1 MPa, providing stronger operational stability.

.QB2 flange model: Pipe diameter range of DN15 to DN50, supporting multiple pressure ratings of PN10/16/25, suitable for high-temperature special scenarios of 0 to 120℃, with the option to add a manual test rod and anti-freezing design to meet outdoor low-temperature conditions.

Quick Selection Techniques for QB2 Exhaust Valve

To quickly select an appropriate QB2 exhaust valve, you can follow these steps:

. Clearly define the basic requirements of the pipeline. First, confirm the type of medium in the pipeline, the QB2 exhaust valve is mainly suitable for clear water and hot water pipelines with a temperature not exceeding 100℃; then, clearly define the nominal pipe diameter and pressure rating of the pipeline. If the pipe diameter is ≥ DN350, it is recommended to replace it with the QB1-10 single-port exhaust valve to avoid insufficient exhaust efficiency.

. Verify special customization requirements. If you have special requirements for the QB2 exhaust valve, you need to explain them in advance during the order placement:

• Special structural length, non-standard flange connection dimensions
• Customized valve body material (such as 304 stainless steel valve body suitable for corrosive water quality)
• Adding a manual test rod, anti-freezing design (suitable for outdoor low-temperature conditions)
• Specifying test, inspection standards and other personalized requirements

. Confirm supply and after-sales support. Choose a merchant that can provide a stock inventory, pre-order selection guidance, and after-sales installation and maintenance services. Some manufacturers can customize various drive devices to meet the upgrade needs of automated pipeline systems. For future orders, a 30% advance payment is required, and the manufacturer will produce according to the requirements.

Parameter Matching Guide for QB2 Exhaust Valve

Accurate parameter matching is the key to the stable operation of the QB2 exhaust valve. The following core parameters need to be carefully checked:

Basic specification parameters matching

Model  Nominal pipe diameter range  Nominal pressure  Connection method  Applicable temperature range

QB2-10  DN40 to DN300  PN10  Flange type  -5℃ to 100℃

QB2-16  DN40 to DN200  PN16  Flange type  -29℃ to +80℃

QB2X  DN40 to DN200  PN10/16  Flange type  0℃ to 100℃ QB2 Flange Model  DN15 - DN50  PN10/16/25  Flange RF Surface  0 - 120℃ (Special High Temperature Model)

Performance Parameters Matching

- **Exhaust Efficiency**: The exhaust capacity of QB2 exhaust valve is superior to that of ordinary double-hole exhaust valve. The DN50 model can exhaust 4 - 173 m³/h per hour, and the DN200 model can reach 27 - 1145 m³/h, quickly discharging the accumulated gas in the pipeline.

- **Sealing Grade**: The mainstream QB2 exhaust valve sealing grade can reach ANSI/FCI70-2 Class IV. It can achieve automatic sealing at a pressure above 0.015 MPa, avoiding water leakage in the pipeline.

- **Negative Pressure Air Supply Capacity**: When the pipeline has negative pressure, the QB2 exhaust valve can quickly supply air at an opening pressure of ≤ 0.02 MPa to prevent the pipeline from collapsing and cracking due to negative pressure.

Material Matching

Part Name  Available Materials  Applicable Scenarios

Valve Body  Gray Cast Iron HT200, Ductile Iron, Cast Steel, Stainless Steel  Cast Iron is recommended for conventional water supply pipelines, while cast steel and stainless steel are suitable for high-pressure/acidic scenarios.

Float Ball  304 Stainless Steel  Suitable for all scenarios, with long service life and corrosion resistance

Installation and Maintenance Guide for QB2 Exhaust Valve

After selecting the correct QB2 exhaust valve, proper installation and regular maintenance can extend the equipment's service life:

. Installation Precautions

• Install vertically at the highest point of the pipeline or at a closed elbow position to ensure that the gas can naturally accumulate in the exhaust valve;
• A protective valve (recommended ball valve Q41F-16 or butterfly valve, gate valve) must be installed below the exhaust valve to facilitate subsequent maintenance and water shutdown;
• If installed in an outdoor low-temperature scenario, choose the anti-freezing type QB2 exhaust valve to avoid water accumulation freezing and cracking the valve body.

. Daily Maintenance Points

• During normal operation, the QB2 exhaust valve valve remains in the open state, and the float ball will automatically cycle for exhaust and sealing actions, requiring no manual intervention;
• During maintenance or cleaning of the body cavity, rotate the valve stem clockwise to close the exhaust valve, and rotate the valve stem counterclockwise to restore the exhaust after the maintenance is completed;
• Regularly check the sealing performance of the float ball. If there is poor exhaust or water leakage, promptly disassemble and repair the sealing parts.

The QB2 exhaust valve, with its stable exhaust and air supply capabilities, is widely used in centralized heating, municipal water supply and drainage, and air conditioning pipeline systems. Through the model comparison, selection techniques, and parameter matching guide in this article, you can quickly find the QB2 exhaust valve that meets the pipeline requirements, ensuring the efficient and safe operation of the pipeline. If you have any questions about QB2 exhaust valve selection customization, you can consult a professional valve manufacturer for one-on-one guidance at any time.