At Onninen, we offer a comprehensive range of control and measurement devices, including professional manometric cocks and tubes, which are essential elements of any heating and hydraulic installation. Our many years of experience show that the proper selection and installation of a manometric cock significantly affects the accuracy of measurements and the safety of the entire installation.
As a market leader in installation, we know that a manometric cock is a device that allows to isolate the manometer from the installation and to vent the measuring system. In Onninen's assortment, you will find manometric cocks from renowned manufacturers that ensure reliable operation in various operating conditions.
Check manometric cocks and tubes at Onninen warehouse
Basic functions of a manometric cock in installations
The manometric cock performs several key functions in the installation. Its main task is to separate the manometer from the measured medium, which allows for the safe replacement of the measuring device without the need to drain the entire installation.
Pressure flow control
Our team of experts recommends using the manometric cock for precise regulation of pressure access to the manometer. With this solution, you can:
- Control the manometer readings by opening and closing the flow
- Protect the device from sudden pressure spikes
- Perform zero indication calibration at atmospheric pressure
- Extend the lifespan of the manometer in installations with pressure pulsations
Ventilation system
In Onninen's offer, you can find manometric cocks equipped with a venting screw, which allows for the removal of air from the measuring system. This function is particularly important in hydraulic installations, where the presence of air can significantly affect measurement accuracy.
Types of manometric cocks available at Onninen
Our branches throughout Poland offer various types of manometric cocks tailored to the specific requirements of installations.
2-way cocks
Two-way cocks are the most popular solution in standard installations. An example is the AMC 2-way manometric cock with G1/2" connections and a nominal pressure of PN25. This model features:
- A body made of corrosion-resistant brass
- A maximum operating temperature of up to 100°C
- The ability to work with water and a mixture of water and glycol
- A built-in venting screw
3-way cocks
Three-way cocks allow for more advanced flow control, enabling switching between two pressure sources or connecting additional control devices.
| Type of cock | Application | Advantages |
|---|---|---|
| 2-way | Standard installations | Easy installation, reliability |
| 3-way | Systems requiring control | Testing and comparison capability |
Proper installation of a manometric cock
From our experience in the installation industry, we know that the correct installation of a manometric cock is crucial for its reliable operation.
Preparation for installation
Before starting the installation, check the compatibility of threads and working pressures. In Onninen's assortment, there are cocks with various types of connections - from standard G1/2" to special M20x1.5.
Installation steps
Our specialists recommend the following installation procedure:
- Ensure that the flow direction is consistent with the arrow on the cock body
- Use appropriate flat seals for threaded connections
- Connect the cock to the installation via a siphon tube (especially in high-temperature installations)
- Install the manometer in the designated connection on the other side
- Tighten the connections to achieve sealing, but do not use excessive force
Installation position
We recommend installing the cock in a position that allows easy access to the control lever. In case of spatial constraints, the handle of the cock can be rotated 180° without affecting the functionality of the device.
Operating the manometric cock in practice
Proper operation of the manometric cock extends its lifespan and ensures accurate pressure measurements in the installation.
Working positions of the cock
The manometric cock can operate in three basic positions:
- Open position: The handle is aligned with the body - pressure reaches the manometer
- Closed position: The handle is turned 90° perpendicular to the body - the manometer is isolated from the installation
- Venting position: With the cock closed, it is possible to loosen the venting screw
Venting procedure
Venting is performed only with the cock in the closed position. In 2-way cocks, a flat, wide screwdriver is used to loosen the venting screw. This process allows for checking the zero indication of the manometer at atmospheric pressure.
Choosing a manometric cock for specific applications
At Onninen, we offer manometric cocks tailored to various types of installations. The proper selection of the device depends on several key parameters.
Technical parameters to consider
When choosing a manometric cock, our advisory team pays attention to:
- Nominal pressure (PN): From PN16 to PN25 depending on the installation
- Medium temperature: Up to 120°C for most models
- Type of medium: Water, water-glycol mixture, technical gases
- Material of construction: CW617N brass for standard applications, stainless steel for aggressive media
Special applications
For gas installations, we recommend impulse cocks that protect the manometer from continuous gas flow. In our assortment, you will also find cocks with a button, allowing for a momentary pressure check without the need to fully open the valve.
Frequently asked questions
Why is a manometric cock essential in heating installations?
The manometric cock protects the manometer from damage and allows for safe maintenance. It allows for isolating the device from the installation during replacement, venting the measuring system, and checking the zero indication. In installations with pressure pulsations, it significantly extends the lifespan of the manometer.
How to recognize the open and closed positions of the manometric cock?
The cock is open when the handle is parallel to the body and the direction of flow. Turning the handle 90 degrees (perpendicular to the body) closes the cock and isolates the manometer from the installation. This position also allows for venting the system through the venting screw.
What are the differences between a 2-way and a 3-way cock?
A 2-way cock has one inlet and one outlet, designed for basic flow control. A 3-way cock has an additional control connection, allowing for the connection of a second manometer or testing device. Three-way cocks are used in systems requiring precise control or comparison of readings.
Does the manometric cock require regular maintenance?
Maintenance of the manometric cock is minimal but important for reliable operation. It is necessary to regularly check the tightness of connections, clean the valve mechanism, and monitor the ease of turning the handle. In case of jamming or leaks, it is necessary to replace seals or the entire device.
What medium can flow through the manometric cock?
The manometric cock can work with water, a water-glycol mixture, and technical gases. The glycol concentration must not exceed 50%, and the medium temperature must be a maximum of 120°C depending on the model. For aggressive media, stainless steel cocks with appropriate seals are recommended.
When to use a siphon tube with a manometric cock?
The siphon tube is recommended when measuring media at high temperatures or containing impurities. It protects the manometer from direct contact with the hot medium and allows impurities to settle in the siphon loop. In heating installations with AMC cocks, its use is standard.
How to perform a leak test on the manometric cock?
The leak test is performed by checking the stability of the manometer readings in the closed position of the cock. After closing the cock, the readings should not change despite pressure fluctuations in the installation. Additionally, check for leaks from threaded connections and from the cock mechanism during operation.
Professional solutions for demanding installations
As a market leader in installation, we offer not only standard manometric cocks and tubes but also comprehensive technical advice. Our team of experts will help you choose optimal solutions for each installation, taking into account the specifics of the medium, operating parameters, and safety requirements.
In Onninen's offer, you will find products from trusted manufacturers that ensure long-lasting reliability and measurement precision. The availability of products in our warehouses and the network of branches throughout Poland guarantee quick order fulfillment for professional installers.
Also, check out our practical guide on disconnecting and connecting the manometer, which contains detailed instructions for safe operation with measuring devices in various types of installations.