Liquid Cooling

Silicone v EPDM Hoses for Liquid Cooling

  • Benefits of Silicone hoses in Data Centre (DC) applications 
  • Silicone v EPDM technical comparison
  • Continuous developments

Hydraflex have been supplying hoses to the liquid cooling market since 2011 with their DataCool Silicone hose assemblies which was developed specifically for the DC market. The choice of silicone over a traditional elastomer such as EPDM rubber was decided based on the requirements of a liquid cooling system and the potential for a dramatic change in performance as LC became more popular.

As with most products, there are two angles of approach, either “how cheap can I get it for” or the “technical” approach, with the latter being the approach Hydraflex made from the start. The application demanded a hose that inspired confidence, was a proven product, and offered security through longevity and the assembly manufacturing process. For this reason, the company partnered with a UK silicone manufacturer to produce the hose, which has been used in DCs since 2011.

Benefits of Silicone hoses in DC applications

Silicone is an inorganic polymer comprising of carbon, hydrogen, and oxygen (along with Silicone). Silicone is used across many industries and applications. Silicone rubber has several advantages but is most known for its resistance to extreme temperatures. Unlike EPDM, silicone stays stable and keeps its physical properties up to 170°C+ (338°F). Not only is silicone excellent in extreme heat, but it is also seen as a sterile elastomer.

Another significant benefit, and very relevant to its use in DCs, is the flexibility of a silicone hose. Not only does it bend like a regular hose, it offers torsion movement, making it very suitable for rear door coolers. 

Silicone is seen as the superior elastomer to EPDM due to its added benefits and generally providing longer life in service, meaning less replacement costs and/or downtime.

Silicone v EPDM Hoses for Liquid Cooling
Silicone v EPDM Hoses for Liquid Cooling

An often-forgotten feature of silicone over EPDM rubber is that silicone has a greater ability to dampen noise transfer and vibration due to the lower hardness of the material. 

Silicone v EPDM technical comparison 

The temperature capability of rubber is important in applications that have varying temperature ranges or can be subjected to high temperatures either in the fluid being conveyed or the ambient temperature where it is fitted. 

Silicone v EPDM Hoses for Liquid Cooling
Silicone v EPDM Hoses for Liquid Cooling

Choosing the incorrect rubber can result in the material suffering prematurely or failure occurring as the rubber reacts with a heat source, whether a single peak or prolonged exposure to heat. 

When compared with silicone rubber, EPDM is significantly inferior, with a maximum temperature of circa 110°C (230°F). Silicone can reach constant temperatures of 170°C (338°F) with higher working temperatures available from VHT silicone grades. 

Although these temperatures may never be achieved, under normal circumstances, continued operation at a higher temperature is likely to reduce the life expectancy of a hose. 

Another benefit of silicone is the high ignition temperature of around 450°C/842°F, potentially removing the need for a fire-retardant black rubber hose, as at these temperatures, most other parts of a DC system would have failed. In the unfortunate event of a fire, the fumes given off are also much less dense and tend to be white (silica) rather than the black fumes given off by other rubbers.

Silicone, by its nature, is unlikely to leach chemicals back into the conveyed fluid from the hose material. In contrast, it is possible from some EPDM rubber hoses causing contamination of the fluid being pumped around the liquid cooling system. 

Silicone v EPDM Hoses for Liquid Cooling
Silicone v EPDM Hoses for Liquid Cooling

Continuous development 

In an industry such as DCs and liquid cooling that is evolving at a rapid pace, any product considered for use in that environment must have the potential to meet tomorrow’s demands as much as todays.

Since the company’s introduction into the liquid cooling market, Hydraflex have supplied thousands of DataCool hose assemblies that are currently operating on liquid cooling systems in Data Centres around the six continents. A key part of this success has been the continual consultations held between Hydraflex and our customers to gain better understanding on industry requirements and product capabilities, which also applies to the entire DataCool product range, including the quick connect couplings. 

In addition to the standard ranges, larger volume users can benefit from the personalisation of products to meet their own requirements more closely.

Geoff Kelley, Commercial Director, or any of the team at Hydraflex Plumbing and Cooling Hoses Division can be contacted at your convenience for any further information on the DataCool Silicone hose assemblies or any other products in our DC ranges. 

[email protected]      +44(0)1634 200 280