Messer produces and delivers high value gases to industrial, Chemical, oil and gas industries. Compressors are custom designed for the duty initially specified by the client. Actual duty needed in sites may vary during the compressor lifetime.

Helium is compressed by a hybrid compressor technology mixing reciprocating piston head for the first 3 stages, and a diaphragm head for the 4th stage. The compressor designed and constructed in 1986, elevate Helium gas pressure from 1,1 bar to 200 bar. Helium gas temperature dramatically increases during compression. Multiple stage construction allows the gas cooling between each compression heads.

Messer developed bottles that can be filled at 300 bar instead of 200 bar. This permits to store and transport 33% more gas without modification of bottles size. It is a non negligible source of savings. Howden as OEM conduct the feasibility study and propose a retrofit operation plan. Solution can bring an answer to customer objectives being a short term solution in place at competitive costs, keeping the filling station available as much as possible. Solution should not require major modification in site to limit procurement and integration costs.

Messer can purchase a new compressor or consider a retrofit solution. Retrofit is a short term, and cost effective solution. Nevertheless it is conditioned by feasibility aspect in particular for a multiple stage compressor technology.

Howden pass compressor through a recalculation targeting the running with the new operating conditions. Outputs of the study show that the new discharge pressure can be obtained with the modification of the final compression head and related pressure vessels.

The total increase of pressure ratio between compressor suction and discharge is split on the 4 compression stages. Change on the 3 first stages has very limited impact and is all compatible with piston stages initial design. Therefore the 3 first stages of compression can remain unchanged.

Change is at 4th stage diaphragm head to reach the new pressure. The design pressure of equipments downstream of the compressor is changed to 350 bar. The after cooler mechanical and thermal design is revised to consider not only the higher pressure but also gas temperature elevation due to higher compressor pressure ratio.

New safety valve and back pressure valve are installed at the compressor final stage for the new pressure delivery.

The absorbed power is increased from 66 to 81 KW, and a technical check confirms that installed driver is capable to stand this higher power consumption. A new oil cooler will be installed since higher absorbed power need higher heat dissipation capabilities.

Hydraulic circuit components are adjusted to the higher pressure. A visual control system is implemented allowing the survey of oil return into the crankcase.

EC machine directive check result on the installation of warning panels near hot points. Project total amount is approximately 80k€ including service on site. This amount corresponds to one third of the acquisition and integration costs of new compressor.