Some of the intrinsic disadvantages of stainless steel components, namely higher investment costs and longer equipment construction and setup times, can be minimized by optimizing design and installation approaches. Such procedures rely on process-oriented project-management methods and use sophisticated software tools, such as Intergraph PDS, an intelligent computer-aided design/engineering (CAD/CAE) application for plant design, construction, and operations.
Construction time can be shortened by using skid or super-skid structures as well as generating piping isometrics directly from 3D-planning tools and utilizing prefabricated pipe spools from specialized and qualified centralized workshops. These efforts need to be coordinated with the logistics department to arrange for the just-in-time delivery of the spools to the construction site. These measures help shorten design and delivery times substantially, improve systems’ reliability, facilitate intercontinental data exchange, and decentralize project teams.
During pipe installation the number of weld seams is significantly lowered if bent piping is used rather than welding elbows. Bending (Figures 1A and 1B) and collaring (Figures 2A, 2B, and 2C) technology, along with advanced orbital welding techniques, permits savings of up to 40% on the piping construction and associated quality assurance costs at significantly shorter realization times.
Bending is applicable up to DN 50 for pipes according to the EN ISO 1127 standard. For Imperial (OD) as well as for DIN 11850 standards, this technology is applicable up to DN 25.
For larger diameters [32<DN<50, Imperial and DIN 11850], bending is optional since some specific technological requirements are needed due to different wall thickness.
Collaring for aseptic design pipe-work is applicable for run pipe dimensions up to DN 200 in combination with collar dimensions of DN =< 65, depending on the run pipe diameter. For larger collar dimensions, standard collaring can be used.
Manufacturers of stainless steel systems incorporating the approaches described in this article achieve significantly lower installation costs and accelerated completion of projects, flexibility in the design phase, systems’ operational reliability, reproducibility, and safety.
The bottom line is that no general statement can be derived on which approach is superior: single-use or stainless-steel system. The decisive criteria for which technology to select includes the expected volume requirements of the product(s) to be manufactured, the requested flexibility in case of multiproduct activities, and resultant capacity planning with associated volume constraints.