A proactive maintenance program not only reduces the risk of unexpected failures, but also helps lower operating costs and ensures the pump is ready for an emergency.
Just Ask Engineering: Pump Life Expectancy
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Apparatus Components
The Role of the Thermal Expansion Valve (TXV)
The TXV performs two tasks. First, it monitors the temperature of the evaporator core outlet. Second, it controls the amount of refrigerant entering the evaporator core inlet.
Industry Trends and Priorities: Needs vs. Wants
Apparatus committees must have foresight and look beyond the excitement of the newest gadgets and technology to make decisions that will serve their departments for the next 10 to 20 years.
The Principle of Latent Heat
Latent heat disappears, but that heat does not cease to exist, just that we cannot measure it with a thermometer. Understand how making use of latent heat is what makes an HVAC system efficient.
Inside Darley: September/October 2026 Edition
Pump modules have been a growing area for the company as fire truck builders have long backlogs coming in. Darley has been able to help fill those needs.
After-Hours Emergency Repairs and Managing a Reserve Fleet During Peak Demand
Apparatus failures do not wait for normal business hours. When these situations occur, fleet personnel must make rapid decisions that balance operational readiness, staffing limitations, and safety.
HVAC Systems: So, What Is a Micron, Part 2
Do you need a micron gauge? That is an economic decision, but if you are conscientious as well as under time constraints, you may find that a micron gauge saves time by avoiding either over pumping to be on the safe side or just hoping that you get enough of the air out.
HVAC Systems: So, What Is a Micron, Anyway?
The tool salesman tries to sell you a micron gauge for your HVAC repairs. What is going on here? How are filters, vacuum pumps, and (ex)planets related?
Emergency Vehicle HVAC Balance
How is balance relevant to the HVAC system? The short version is that the amount of refrigerant must be balanced with the interior volume of the system.
What the HVAC System Needs
The HVAC technician’s duty when performing maintenance is to understand each component clearly and inspect for anything that could impede its function.
Introduction to Emergency Vehicle HVAC: What is Heat?
The concept is how can we move the heat from inside the box to outside the box? It really doesn’t matter what the box is.
Just Ask Engineering: What Makes a Part Reusable or Not?
When rebuilding a pump, deciding what to replace versus reuse is a common question. Fortunately, the process is straightforward: break the pump into individual components and evaluate each piece one at a time.
