What is an appropriate distance between the steam trap inlet and the main pipe?

It should be introduced vertically into the ground first, and then the drain valve should be connected. Thermostatic valves are generally installed horizontally!

Whether the steam trap is placed horizontally or vertically depends on its type； They are mostly placed horizontally. There is no strict specification regarding the distance from the main steam pipe. Placing it in the air helps prevent burns from high temperatures and saves space ； Place it on the ground for easy inspection and maintenance.

Place it in a location that is easy to operate; the water inlet should be at the bottom of the pipe. In principle, the pipe section between the bottom of the main pipe and the steam trap should not be too short, otherwise the steam trap will activate too frequently. It is best to place it on a horizontal pipe

Those that are seen frequently are at a height on the ground that is easy to operate.

Since traditional check valves contain moving parts, they are generally of the float ball or inverted bucket type, with some also being of the disc type. Over time, the internal sealing surfaces become severely damaged, resulting in an increased air leakage rate. The internal structure determines the installation method; most of them are installed horizontally. It is necessary to consider whether future replacement and maintenance operations will be convenient.

It’s better to put it at the very end, to prevent freezing

The standard practice is to install a water reservoir in the pipeline and then connect a steam trap to it; the steam trap should be placed near the ground for easy maintenance, with its orientation determined based on the type of steam trap.

This post was last edited by Watt Energy Saving on 2019-4-29 at 16:36. Piping and Installation of Steam Traps – By Zhong Yuyu from the Technical Department of Hangzhou Watt Energy Saving Engineering Co., Ltd. For steam traps to function properly, in addition to selecting the right type of trap, proper piping and installation before and after the trap are also necessary. The pipeline before the steam trap refers mainly to the drainage system from the equipment to the trap. The condensate flows to the steam trap through the drainage outlet of the steam-using equipment; since the pressure inside the equipment and the steam trap is the same, the flow is driven by the gravity of the condensate. Therefore, the steam trap must be installed below the equipment. The piping layout between the device’s drainage point and the steam trap should have a certain slope. If it is not possible to adjust the installation of the steam trap at the lowest point on site, a sleeve siphon mechanism must be used. Watt Energy-saving steam engineers recommend to customers a flow rate that is based on maintaining the lowest possible pressure drop. The diameter of the steam trap does not necessarily have to be the same as the diameter of the drain pipe connection. Because the equipment must be designed to handle different working pressures and flow rates. When selecting the diameter of the condensate pipe, the amount of condensate allowed to be discharged is not necessarily the drainage volume when the equipment is operating at full load. At startup, the amount of condensate can be up to twice the operating load. At the same time, there is also air present in this portion of the piping system. Typically, the calculated displacement is actually based on twice the steam load and 1.4 mbar of frictional resistance per meter. The condensate pipeline behind the steam trap, that is, the trap discharge pipe, refers to the condensate pipeline from the outlet of the steam trap to the main condensate recovery pipe or the atmosphere. This pipeline contains not only condensate, air, and other non-condensable gases, but also secondary steam generated as a result of pressure reduction. Whenever possible, the piping should be as low as possible. Consider the various actual conditions: at startup, the condensate is relatively cold, and there is little or no secondary steam. But at the same time, the amount of condensate water is the highest, and it also includes some air. The diameter of the pipe must be at least the same as the diameter of the steam trap inlet. After running for some time, the amount of condensate stabilizes at the operating load. But as the temperature of the condensate rises to near the steam saturation temperature, secondary steam is also generated. When selecting the drain pipe for a steam trap, the amount of secondary steam is the most important parameter. The selection of the condensate pipe downstream of the steam trap is based on the diameter chosen for the secondary steam. Considering costs, the condensate main is always kept as small as possible. Usually, the amount of water to be treated is taken into consideration during design, but in reality, what is discharged from the steam trap is always a mixture of condensate and secondary steam. Not everyone is aware that the volume of secondary steam can be as high as 400 times that of the condensed water. This indicates that the diameter of the condensate recovery pipeline should be determined based on the steam volume rather than the condensate volume. At saturated temperature discharge, secondary steam accounts for over 99% of the total volume in the condensate pipeline, while the volume of condensate makes up less than 1%. The secondary steam occupies almost the entire volume of the pipe. The condensate will flow at the bottom of the pipe, at a speed lower than that of the secondary steam. Its mass flow rate, plus the mass flow rate of steam, constitutes the total mass flow rate of the fluid passing through the steam trap. Due to the presence of condensate at the bottom of the pipes, the steam will inevitably be very humid. Therefore, the flow velocity of the secondary steam must be limited to 15 m/s; otherwise, water hammer and erosion will occur in the bends. In their daily work, Watt Energy Saving’s steam engineers have found that the feasibility of connecting several steam traps operating at different pressures to a single common recovery main is often questioned. This is because it is believed that high-pressure condensate may interfere with the discharge of low-pressure condensate. However, one fact is overlooked: high or low pressure exists only within each steam trap; at the outlet of the steam trap, the pressure is that of the common recovery pipe, perhaps plus the back pressure generated by the movement of secondary steam. If the piping is undersized, it is certainly possible for the backpressure to rise excessively, thereby restricting or even preventing the drain valve from functioning.

This post was last edited by Watt Energy Saving on 2019-4-29 at 16:38. Selection and determination of pipes before and after steam traps – Hangzhou Watt Energy Saving Engineering Co., Ltd., Zhong Yuyu. An inappropriate selection of pipes before and after steam traps can affect the proper drainage of condensate as well as the proper functioning of the traps. The pipeline before the steam trap refers mainly to the drainage system from the equipment to the steam trap. The condensate must flow from the drainage outlet of the steam-using equipment to the steam trap. The pressure inside the equipment and the steam trap is the same; therefore, the flow will be driven by gravity, so the steam trap must be located below the equipment. There should be a certain drop in the piping layout from the drain point of the equipment to the trap. Watt Energy-saving steam engineers recommend to customers a flow rate that is based on maintaining the lowest possible pressure drop. The diameter of the steam trap does not necessarily have to be the same as the diameter of the drain pipe connection. Because the equipment must be designed to handle different working pressures and flow rates. When selecting the pipe size, the amount of condensate that can be discharged is not necessarily the drainage volume when the equipment is operating at full capacity. At startup, the amount of condensate can be up to twice the operating load. At the same time, there is also air present in this portion of the piping system. Typically, the calculated displacement is actually based on twice the steam load and 1.4 mbar of frictional resistance per meter. Based on experience, Watt Energy-Saving Steam Engineers recommend the following operating loads for steel pipes: for pipes with a diameter of 15 mm, the recommended load is 100 kg/h; for 25 mm pipes, it’s 500 kg/h; for 50 mm pipes, it’s 3000 kg/h; for 65 mm pipes, it’s 6000 kg/h; and for 100 mm pipes, it’s 20,000 kg/h. For example, if the required operating load is 2000 kg/h, then a 50 mm diameter pipe should be used. The pipeline behind the steam trap, that is, the steam trap discharge line, refers to the section of pipe at the outlet of the steam trap; this pipe contains not only condensed water, air, and other non-condensable gases, but also secondary steam generated as a result of pressure reduction. Whenever possible, the piping should be routed downward as steeply as possible to connect to the following equipment: • Secondary steam recovery tank • Surge tank for the condensate pump • Boiler feedwater tank or deaerator. Consider the actual operating conditions: at startup, the condensate is relatively cold, and there is little or no secondary steam. But at the same time, the amount of condensate water is the highest, and it also includes some air. The diameter of the pipe must be at least the same as the diameter of the steam trap inlet. After running for some time, the amount of condensate stabilizes at the operating load. But as the temperature of the condensate rises to the steam temperature, secondary steam is also generated. Calculations performed by Watt Energy Saving Steam Engineers show that: Ratio of secondary steam: Pressure before the trap = 4 barg; Secondary steam pressure (pressure in the condensate pipe) = 0 barg (directly discharged to the atmosphere). Percentage of secondary steam = 10%. When selecting a drain pipe for the steam trap, the amount of secondary steam is the most important parameter. The selection of the condensate pipe downstream of the steam trap is based on the diameter chosen for the secondary steam. Considering costs, the condensate main is always kept as small as possible. Usually, the amount of water to be treated is taken into consideration during design, but in reality, what is discharged from the steam trap is always a mixture of condensate and secondary steam. Not everyone is aware that the volume of secondary steam can be as high as 400 times that of the condensed water. This indicates that the diameter of the condensate recovery pipeline should be determined based on the steam volume rather than the condensate volume. Looking at the previous example again: the pressure at the steam trap is 4 barg, while the pressure in the recovery pipe is at atmospheric pressure. The amount of secondary steam is about 10%. The condensate load is 1000 kg/h, which means that in the discharge pipeline, each kilogram of discharged fluid consists of 0.1 kg of steam and 0.9 kg of water. Of this, secondary steam accounts for 99.44% of the total volume, while condensate accounts for 0.56% of the volume. In other words, the secondary steam occupies almost the entire volume of the pipeline. (Usually, since the discharge pressure is slightly higher than atmospheric pressure, the amount of secondary steam released is also slightly less.) The condensate will flow at the bottom of the pipe at a speed lower than that of the secondary steam. Its mass flow rate, plus the mass flow rate of steam, constitutes the total mass flow rate of the fluid passing through the steam trap. Due to the presence of condensate at the bottom of the pipes, the steam will inevitably be very humid. Therefore, the flow velocity of the secondary steam must be limited to 15 m/s; otherwise, water hammer and erosion will occur in the bends. From a practical perspective, there are other factors to consider when selecting pipes. Temperature control. If the device features temperature control, the pressure will drop by nearly half when the control valve is partially open. This phenomenon occurs when the equipment is operating at full load and the valve is selected based on the critical pressure drop. But sometimes the valve does not need to be selected based on the critical pressure drop, in which case the pressure drop will be much less than half. For example, when the pressure downstream of the control valve decreases, the amount of secondary steam generated is reduced. Thermostatic steam traps. These types of steam traps [such as pressure-balanced steam traps or bimetallic steam traps] are designed to drain water at temperatures below the saturation temperature. For different types of steam traps, the temperature difference can range from 10 to 50ºC. For example, the liquid chamber of a pressure-balanced steam trap is designed to operate at temperatures 13ºC below the saturation temperature. This will reduce the amount of secondary steam generated. Below is an example for selecting the main condensate recovery pipe: The saturation temperature at 7 barg is 170.5ºC; saturation temperature minus 13ºC equals 170.5 – 13 = 157.5ºC. According to the steam table, the pressure corresponding to 157.5ºC is 5.00 barg. Therefore, the upstream pressure should be set at 5 barg, rather than 7 barg. This will reduce the diameter of the condensate pipe. Starting load. The starting condition refers to the state where, when the equipment is cold, the amount of condensate water is at its maximum. The methods for calculating the starting load vary greatly; manufacturers often simply multiply by a factor (2 or 3) based on experience. For equipment that is not used frequently, it is appropriate to select it using the starting load. Sometimes, for a particular plant, not all equipment is in use at the same time; therefore, these variations must be taken into account. For example, in a laundry room, hot water needs to be heated at startup for washing clothes. Then a dryer is used, followed by a steam iron. The use of flash tanks in equipment and deaerators in boiler rooms means that the pressure in the main condensate pipe is higher; in such cases, care must be taken to ensure that this increase in pressure does not affect the performance of the steam traps. In their daily work, Watt Energy Saving’s steam engineers have found that the feasibility of connecting several steam traps operating at different pressures to a single common recovery main is often questioned. This is because it is believed that high-pressure condensate may interfere with the discharge of low-pressure condensate. However, one fact is overlooked: high or low pressure exists only within each steam trap; at the outlet of the steam trap, the pressure is that of the common recovery pipe, perhaps plus the back pressure generated by the movement of secondary steam. If the piping is undersized, it is certainly possible for the backpressure to rise excessively, thereby restricting or even preventing the drain valve from functioning.

For horizontal placement, it also depends on the type of drain valve. Easy to maintain; areas where it won’t cause harm to people