How to maximise the lifespan and safety of steam hoses

19 November, 2024

Steam is integral to numerous industrial processes, yet working with it poses significant risks and costs. Ensuring the proper maintenance and handling of steam hoses is crucial to enhancing safety and extending their service life. By adhering to best practices, businesses can prevent common issues such as superheated steam damage, popcorning, and leaks, thereby safeguarding both their equipment and personnel.

Understanding steam and its impact on hoses

Steam plays a vital role in many industrial applications, but its various forms can have significantly different effects on steam hoses. Steam exists in three states: wet saturated steam, dry saturated steam, and superheated steam, each determined by the combination of pressure and temperature.

Wet saturated steam contains unvapourised water particles, giving it a partially liquid form. This type of steam tends to have a lubricating effect on the rubber inner walls of hoses, which can be beneficial in preventing wear. However, excessive water particles may lead to wear and tear over time if not controlled.

Dry saturated steam, on the other hand, reaches a point where it no longer contains liquid water particles but is still at the boiling point. This type of steam can be harsh on hose materials if not managed properly, as it can cause the inner rubber walls of the hose to become brittle, increasing the risk of cracks and eventual failure.

The most critical form of steam to manage is superheated steam. When steam is heated beyond its boiling point without an increase in pressure, it becomes superheated. This steam state is extremely dry and can continue the vulcanisation process of the hose's rubber inner wall, leading to hardening and reduced flexibility. Superheated steam accelerates the degradation of the hose, shortening its service life significantly.

To mitigate these risks, it is essential to closely monitor the operating pressure and temperature, ensuring they do not exceed the recommended limits for the hose. By maintaining steam within safe parameters, businesses can significantly extend the lifespan of their steam hoses and enhance overall safety.

Best practices to avoid hose damage

Proper management and maintenance are crucial in extending the service life of steam hoses and preventing common forms of damage. One of the primary concerns is preventing damage from superheated steam. To avoid this, it is vital to monitor the operating pressure and temperature carefully, ensuring they do not exceed the hose's specified limits.

Another significant issue is the phenomenon known as ‘popcorning’, which occurs when the inner wall of the hose absorbs water or water vapour. After use, the hose cools, causing the steam inside to condense into water. When the hose is subsequently reheated, the trapped water vapour expands dramatically, creating air bubbles that form blisters on the inner wall. To prevent popcorning, it is essential to blow the hose dry after each use, ensuring it is completely dry before storage.

In addition to proper drying techniques, using steam hoses with extruded inner walls can further mitigate the risk of popcorning. These hoses feature a seamless, homogeneous inner wall made of superior gas-tight rubber, which is resistant to water vapour penetration.

To ensure the structural integrity of steam hoses, it is also advisable to use hoses with galvanised steel inlays. Standard steel inlays can rust when exposed to water vapour, weakening the hose from within. Galvanised steel inlays, however, are more resistant to corrosion, significantly reducing the risk of internal damage and prolonging the hose's lifespan.

Ensuring structural integrity and safety

The structural integrity and safety of steam hoses is paramount to maintaining a secure and efficient industrial environment. A critical aspect of maintaining hose integrity is the use of galvanised steel inlays. Standard steam hoses are often fitted with steel inlays that are prone to rusting when exposed to water vapour. This rusting process can occur below the surface, invisible to the user, and can lead to significant weakening of the hose.

In addition to using corrosion-resistant inlays, it is essential to ensure that steam hoses are clearly marked. According to the EN ISO 6134-2A standard, steam hoses should be clearly marked with important product information, including the name of the producer, the standard with which the hose complies, the maximum operating pressure, and the maximum permissible temperature. Moreover, a red stripe running the length of the hose serves as a visual identifier that the hose is designed for steam.

To improve safety and ease of identification, it is recommended to use a spiral colour stripe with clear, printed text along the hose. This design ensures that the hose type is easily recognisable even in areas that are hard to reach.

Preventing steam leaks

Preventing steam leaks is crucial not only for maintaining the efficiency of operations but also for ensuring the safety of personnel. Leaks can occur due to issues with the hose itself or from loose clamp connections. To avoid unnecessary costs and dangerous situations, steam hoses are typically fitted with steel Boss clamping plates or high-pressure brass gripper clamps.

Boss fittings are known to begin leaking over time due to their oval shape and the opening where the two-part plates connect. A more effective solution is to use brass gripper clamps, which reduce the frequency of leaks. However, even these clamps do not eliminate the issue entirely, as the space between the two-part grips can still allow for some leakage.

To put an end to steam leaks and loose fittings, the use of press sleeves is recommended. High-quality steam hoses, such as the Goodall Inferno Steam Hose, combined with assemblies crimped with Goodall DuraCrimp ferrules, lock the ferrule into place with a special design interlock groove, forming a superior permanent connection. These galvanised steel DuraCrimp fittings and ferrules are Cr6-free, having no negative impact on the environment while ensuring a secure and leak-free connection.

Proper hose installation and regular inspections

Proper installation of steam hoses is crucial for ensuring their longevity and safety. It is important to check that the hose is installed correctly, with no sharp kinks behind the fittings, that it is free of tension and torsional stress. During installation, the fittings and hose connection should be checked at operating pressure. This should be done slowly and gradually to ensure there are no leaks.

Regular inspections are essential to maintaining steam hoses in good condition. Any issues encountered during routine checks should prompt immediate action to correct the problem. Steam hoses may sustain damage internally, which can be difficult to detect without professional help. Therefore, it is advisable to have hoses inspected regularly by specialists who can thoroughly examine and test them.

Steam hose tests should be conducted in accordance with ISO 6134 guidelines, which recommend a pressure test every six months. By adhering to these standards, businesses can ensure their hoses are safe and effective for use.

******************************************************************************************************

For those seeking additional guidance on steam hose maintenance, ERIKS provides a range of professional services designed to enhance performance and safety. Its service exchange programme includes thorough external visual inspections and endoscopic evaluations for superheated steam and other aggressive media. By implementing the best practices outlined in this article and leveraging experts such as those at the ERIKS Hose Centre of Excellence in Northampton, businesses can maximise the lifespan of their steam hoses while maintaining a safe and efficient industrial environment.

For further information please visit:

https://eriks.co.uk

******************************************************************************************************

https://twitter.com/ERIKS_UK

https://www.linkedin.com/company/eriks-uk/