Gas Patio Heater Regulator
It is important to know how to use a propane patio heater if are looking to keep warm in the cold weather. Matthew Griffith, chief of the prevention section at the Montreal Fire Department, advises that consumers be looking for products that have safety certifications.
It's also crucial to make sure that there are there are no nearby combustible objects and that the patio heater is correctly connected.
Pressure Regulator
Gas regulators are simple mechanical appliances that we use in our cars and homes every day without giving them a second thought. Their invention first introduced 135 years ago, has revolutionized the way natural gas and propane is used for cooking, heating and oxyfuel welding. The fundamental purpose of regulators is the same, but there are many variations. The regulator is based on an element that senses pressure which is usually a fabric reinforced diaphragm, which controls the position of the valve plug and restrict the flow of gas.
The diaphragm connects to the stem of the valve by rods that go through the set spring, up through the diaphragm, and finally into the valve. The mechanism is able to detect the gas pressure in the house or pipeline and adjusts the position of the valve plug to match the demand. As the consumption of gas in the house decreases and the pressure between the regulator and the house reduces as well. This causes the diaphragm to deflate downward, and it moves the valve plug closer to the orifice, which limits the flow. As the gas demand increases in the home the valve will open more, thereby increasing the flow.
The valve plug is shut until the demand of the house decreases. This opens the valve to increase the flow. This process, also known as sizing, is the fundamental operation of the regulator.
When the valve is opened it creates pressure up in the main chamber of the regulator, which is connected to the port for hose outlet with the venturi tube (see the image). This pressure is controlled by changing the screw or handle located on the exterior of the regulator. When the screw is turned counterclockwise, it moves up and reduces the pressure. However, when it is turned clockwise, it decreases the pressure.
When choosing a regulator for pressure be aware that the maximum and minimum nominal pressure is set by commercial standards, not the pressure of the gas in the supply line. The regulator should also be compatible with your hose. Choose a hose which is whistle-free, that has various sizes of rings to stop resonant sounds from accumulating along the length of the hose.
Thermocouple
Thermocouples are based upon the principle that two dissimilar metals in contact at each end produce a voltage even when they are at extremely different temperatures. They are used to measure the temperature difference between two points in a system and transform this information into an electrical signal that can be read by thermocouple meters or any other instrument. Thermocouples offer a number of advantages over conventional sensors such as thermistors, including the ability to measure extremely high temperatures and to function in harsh environments.
The measuring (or hot) junction is created by joining two metals that are not compatible at one end, and the other end, known as the reference (or cold) junction, is maintained at the same temperature. Thermocouples are passive devices, which means they don't require power in order to function. The voltage generated is proportional the temperature difference between the measuring junction and the reference junction. Manufacturers of thermocouples and organizations that offer metrology standards, such as NIST, provide reference tables for the function E (T). displaystyle scriptstyle e(T) for each type of thermocouple.
There are three kinds of thermocouple connections: exposed grounded and weld. The exposed style of junction is a bit higher than the protective sheath, and provides the fastest response time. For measurements in corrosive environments it is recommended that a grounded thermocouple be used. A thermocouple welded to a wire is physically separated from the sheath with mgO powder to stop the penetration of moisture or gas which could cause mistakes.
The thermocouple that is welded also has the added benefit of being more vibration resistant. It is recommended to use it in harsh environments that require pressures up to 3000 psi. When a thermocouple is damaged, it's typically caused by a lack of polarity. If the sheath isn't correctly polarized, both ends of the thermocouple will have different voltages at the measurement junction, which can cause an incorrect reading and damage the instrument. A sensor that's not properly calibrated or installed can also cause a faulty thermocouple.
Thermostat
In contrast to electric heaters that need to be hardwired into the wall gas patio heaters are portable and use propane or natural gas cylinders to fuel. Thermostats regulate the flow energy into these cylinders in order to ensure that they do not overflow, yet still provide heat as needed. The thermostat does this by sensing the temperature of the air that flows over it. The thermostat also determines if the room is cooling down to a comfortable level and shuts off the heating.
The most common type of thermostat is a digital one. It utilizes a microcontroller in order to convert a fluctuating electrical resistance into an indication of temperature. It can perform this task more accurately than previous mercury switch thermostats that employed a mercury coil with three wires that would move based on temperature. This enabled it to tilt a mercury switch that was connected to the electrical circuit of an air conditioning or heater unit, turning it on or off.
small gas patio heater of thermostat is a mechanical one. The thermostat is activated when the wax inside a small cylinder starts to melt, which is around 180 degrees F. (Different thermostats have different opening temperatures). When the wax is hot, a rod that is connected to the thermostat opens the valve. As the room cools the wax expands and the rod is pushed into the cylinder, closing the valve.
You can also program thermostats to alter the temperature at different time of the day. You can cut down on energy consumption by programming your heating system to be turned off and on while you are working, or asleep, instead of having it always on. You can also set your thermostat to come on earlier so that you will arrive home to an ideal temperature. Thermostats also often include an element called the heat anticipator that prevents the heater from turning off too early. This is because certain parts of the home are at the desired temperature before the thermostat has even been set.
Pilot Light
Many modern homes, heating systems and furnaces have done away completely of pilot lights. However older homes still rely on them to ignite gas in the burner chamber. It is important to know how to safely restart the pilot light if it ever fails.
A pilot light creates small flames that warm the thermocouple. This produces electricity and keeps the gas valve open. When the pilot flame ceases to burn, the thermocouple cools down and stops producing electricity, thus closing the valve. Pilot lights are utilized in the majority of propane and natural appliances, such as fireplaces, water heaters, furnaces, ranges, barbecues and hot tubs.
To light a pilot light, it is necessary that you first shut off the gas valve on the appliance. Then you need to remove any doors or panels that might hinder accessing the pilot light. Follow the instructions on the front of the light to open the tube for the pilot light. After you've lit the pilot light, return the gas valve knob to the "on" position.
Safety is the primary reason for leaving a pilot light on. If you accidentally extinguish the pilot light, the gas constantly venting from the tube can build up in your home until the spark or static electricity ignites the gas and triggers an explosive explosion. To prevent this, the pilot tubes come with an integrated cutoff valve.
A pilot light that is constantly burning is not just hazardous however, it also consumes energy. Various studies have shown that a pilot light can burn between $7 and $18 worth of gas per month. This wasted fuel puts a heavier burden on the air conditioner in the summer. Another issue with the pilot light is that it attracts spiders, which could create webs that block the pilot tubes. Also, a constant flame can release trace amounts of the mercaptan compound that causes the rotten egg odor that is present in natural gas. If you're ever concerned about these issues, you should consider purchasing a gas fire with a remote control or replacing a fireplace with a more effective, modern-day model.
