Renishaw machine tool probes and calibration products are used by FMC Technologies in Dunfermline, Scotland in a preventive maintenance programme designed to check and verify the dimensional accuracy of its CNC machine tools. The resulting data is stored for quick and easy retrieval using Renishaw's CNC Reporter software.
FMC Technologies is a Houston, Texas-based developer and manufacturer of oil and gas Production Control Systems (PCSs) with operations around the world. Consisting of topside controls, power equipment, the Subsea Control Module (SCM), various sensors, and subsea electrical and hydraulic distribution equipment, the PCS is configurable according to conditions and requirements, and provides engineers on-board an oil or gas production platform with precise control of the well.
Craig Simpson and Mike West are FMC Technologies maintenance technicians, responsible for the service and support of 20 CNC machine tools of various types, makes and ages. Also in their charge is one of the company's more recent investments: a £2.5 million, purpose-designed and built SCM machining cell, consisting of two Okuma Space Centre MA-600HB CNC horizontal boring machines, loaded and managed by a Fastems automation system. An SCM contains electronics, instrumentation, and hydraulics for safe and efficient operation of valves and chokes on the well-top ‘subsea tree'.
Wells can be as far as 120km from the production platform, in water up to 10,000 feet deep. When an SCM is installed on the seabed, it has to be reliable and safe for the production life of the well, which can be decades. Hydraulically controlled valves must be free from defects and contamination since any malfunction can be potentially very costly, running to tens or even hundreds of millions of dollars.
The Fastems automated cell is used to machine the stainless steel hydraulic manifold block, which is a critical control element in an SCM assembly. The 267kg block is approximately 400 mm x 400 mm x 400 mm and is a complex of 350-drilled holes. The company will make more than 200 manifold blocks in 2014, when the cell is fully operational and capable of working ‘lights-out’. Should a tool break during the machining cycle, a Renishaw NC4 laser-based tool setting system will detect the tool absence and notify the Fastems system, which will reject the pallet and replace it with another.
FMC Technologies is guided by what it calls the 5-absolutes of quality, the second of which emphasises the importance of prevention, ‘not appraisal’ as the ‘cause’ of quality. Mr Simpson explains that quality control in the new cell is extremely thorough - the finished part is 100% inspected and has to be precise and flawless before it can be shipped to assembly. Stressing the importance of traceability, he adds that they have to be seen to be keeping precise records of their machining processes.
To ensure that its 20 machines are accurate, the FMC Technologies' maintenance department services them all, up to three times annually. All machines are checked with a Renishaw QC20-W wireless ballbar. The Okuma machines are serviced twice a year, at which point machine geometries are checked and rectified. Once a year the company also checks them with a Renishaw XL-80 laser measurement system and linearity is corrected. Every second year, at their annual service, all machines are levelled, aligned and checked with the XL-80 system.
Data from both the Renishaw ballbar and also the Renishaw XL-80 are collected and collated using Renishaw's CNC Reporter software package. Renishaw RMP60 touch probes are fitted on most of the machines, including the Okumas so the maintenance team knows the linear movements are exactly right. FMC Technologies' service contract with Renishaw includes 11 RMP60 touch probes with radio signal transmission, which are replaced annually or when one is damaged.
FMC Technologies initially invested in the CNC Reporter software primarily for keeping production records. But, the company's maintenance department has also found it invaluable and has recently invested in several additional licenses. According to Mike West, the Renishaw package is very useful for comparing data, and not very expensive.
To help speed-up machine checking and calibration in the SCM cell, FMC Technologies has designed and built a custom calibration block, which is mounted on the Okuma machines during scheduled maintenance or when the machine is being checked.
Craig Simpson and Mike West both agree that the Renishaw XL-80 laser measurement system, the QC20-W wireless ballbar and CNC Reporter software are very easy and intuitive to use.
FMC Technologies claims that its Production Control Systems, including the SCMs are used on more than 1,000 subsea wells around the world, with an uptime rate of 99-100%. Nevertheless, Craig Simpson says the maintenance programme in FMC Technologies in Dunfermline is evolving continually. From being far less structured and much more time consuming, the preventive maintenance process is now very well organised with the Renishaw equipment helping them know much more about their machines.
Renishaw Oceania represents the Renishaw Group in Australia.