The MECH pressure switch, model YLKG. It turns a pressure change into an electrical signal for alarm or control. This guide explains what it does and how it works, related models, technical data, the critical point in selection and installation, and common mistakes. For more, read the guide pressure and supervisory switches.
At a glance
- A pressure switch has a diaphragm that moves with line pressure; at the set pressure it changes the state of its electrical contacts.
- Connection: 1/2″-14 NPT.
- Operating temperature: 0 – 80 °C.
Pressure switch: what it does and how it works
A pressure switch has a diaphragm that moves with line pressure; at the set pressure it changes the state of its electrical contacts. It is used on alarm lines of alarm valves, for pressure supervision and for pump control.
Per the product data it comes in several pressure ranges with a 1/2″ NPT connection.
Technical data
| Item | Specification |
|---|---|
| Connection | 1/2″-14 NPT |
| Pressure ranges | 5–20 psi, 15–55 psi, 20–120 psi |
| Electrical rating | 15 A at 125/250 VAC |
| Temperature range | 0 – 80 °C |
| Cover | Tamper resistant screws (optional cover tamper switch) |
Range and setting
Choose the range with the set point near its middle and adjust it to the system design; the wrong range makes the signal inaccurate or inoperative.
Caution
Wiring must follow NFPA 72 and the electrical rating in the product data.
Installation steps
- Install vertically on the alarm line or measuring point.
- Set the operating pressure to the design.
- Wire per the wiring diagram and close the cover with its tamper-resistant screws.
- Test the signal at the panel.
Common mistakes
- Choosing an unsuitable pressure range.
- Leaving the cover open or unscrewed.
- Not testing after installation.
Files and ordering
On this page: Product page (catalogue), MECH Fire Protection Valves Catalogue (UL/FM). Add the product to your request list with size and quantity and we send a quotation, or build a submittal PDF for the consultant. Fu-Mech is the exclusive MECH agent in Saudi Arabia.
Frequently asked questions
What ranges are available?
As listed in the product data on this page.
What is the difference between a pressure switch and a supervisory switch?
A pressure switch operates on pressure change; a supervisory switch operates when a valve is moved. See pressure and supervisory switches.
Is it UL / FM approved?
No approvals are listed for this model in the product data. If your project needs a specific approval, ask us before ordering.
What end connection does it have?
1/2″-14 NPT. Choose the connection that matches the adjacent pipe and fittings.
References
- MECH catalogue — Product datasheet
This guide is general information to help with selection. Figures come from the product data on this page and the MECH catalogue; final design is by the project’s approved designer to the applicable standards and the project specification.
NWC approved
