Water hammer problems in steam pipelines

After the steam supply is stopped, water will surely start to condense in the main steam pipeline. Water hammer will not occur if there is no flow of steam.

After the steam supply is stopped, water will inevitably start to condense in the main steam pipeline. Water hammer does not occur when no steam is used, but if steam is to be used, the water must be removed gradually; otherwise, water hammer will occur.

After the steam is exhausted, if the user stops using it for an extended period of time, even though some of the steam exchanges heat with the surrounding environment and condenses into water, this heat exchange occurs at a relatively slow rate. At that time, the steam flow rate is 0, so no water hammer is generated. However, if the steam is used again and a certain flow rate is established, water hammer will occur if the condensed water cannot be drained.

The main steam pipeline should be equipped with a drain or steam vent; if not, one should be installed when the system is shut down. The absence of such a device is unsafe and does not comply with design specifications.

Without circulation, there should be no water hammer phenomenon

Steam pipes usually have low-point drains... This helps to prevent water hammer from occurring when steam is introduced... If there are no drain valves (in chemical engineering, such valves are not included in the design), then when introducing steam, it is possible to control the flow rate of steam and add it gradually, thereby minimizing the impact of water hammer on the pipelines……

I would like to ask everyone: is it necessary to install a steam trap on the main pipeline within 50 meters? Could thermal losses be significant in this case?

Water hammer is a common problem in steam pipelines; generally, the pipes need to be preheated before steam is introduced, in order to minimize the occurrence of water hammer

It’s hard to say; it would be better for analysis if a heat balance calculation could be done based on the heat transfer capacity of the specific pipes and the steam flow rate, etc.

As long as there is steam and its pressure remains stable, water hammer will not occur; this is somewhat similar to cavitation.

Water hammer occurs when steam in motion is accompanied by water; without water, water hammer cannot be generated. However, steam pipelines all have drain valves – there’s no such thing as a valve that refuses to function. So the error must have occurred during piping installation

A steam trap or steam drain must be installed on the main steam pipeline; in cases where there are no users connected to the steam pipeline, the steam drain should be kept partially open to prevent condensation from forming in the pipeline, which could otherwise cause water hammer when users start using the steam.

Water hammer occurs in the form of waves. It is a common problem in steam pipelines; therefore, it is usual to preheat the pipes when steam is supplied, in order to minimize water hammer effects. After the steam supply is stopped, if the user does not use steam for an extended period of time, any steam that does exchange heat with the surrounding environment and condenses into water does so at a relatively slow rate. At this point, the steam flow velocity is zero, so no water hammer occurs. However, if steam is used again and a certain flow velocity is established, water hammer will occur if the condensed water cannot be completely drained.

If the user does not use steam, water hammer will not occur, because once the steam supply is stopped, the steam in the steam main gradually condenses into water. The temperature of this condensed water increases gradually from the ends towards the center, until equilibrium is reached; the temperature at the contact surface between the condensed water and steam is the saturation temperature at the system pressure. If the steam does not flow, it will not come into contact with the cold condensate water and thus not condense suddenly, causing water hammer. But if the user uses steam again, water hammer will definitely occur.

A steam main of 50 meters should be equipped with a steam trap, at least one one before the user’s inlet valve.

If steam does not flow, water hammer will not occur; it is best to keep the steam trap in the open position, which will prevent water hammer from occurring when steam is supplied again

If the steam in the pipeline does not flow, there will be no water hammer, but if users in the area consume steam, water hammer will definitely occur. It is best to install a steam trap. :loveliness:

Hello, I’m a bit unclear about the concept of water hammer. The term \"steam water hammer\" mentioned here seems to be different from \"water hammer\"; so what exactly is the meaning of \"water hammer\"? Thank you.

I have encountered water hammer; the steam trap didn’t work

That’s how it works. Before starting the equipment, steam needs to be introduced into the production area. Before doing this, a small amount of steam is allowed to flow in first, while the bypass valves on all the steam branches in the production area as well as those next to the heat exchangers are opened to drain any condensate. This is done to prevent water hammer. Once the water has been drained, the corresponding bypass valves are closed, and then steam is supplied at normal levels. When the steam users in the production area stop using steam for an extended period of time, and there are no heat exchangers or steam drainage valves in the main steam pipeline, some condensate will accumulate in that pipeline. Generally, heat exchangers should be installed along steam pipelines every 40–50 meters, and they should remain open while steam is flowing. As mentioned by the original poster, since there is no flow of steam, water hammer cannot occur between the steam and its condensate in the main steam pipeline.