12
Foundation
Introduction
Vilter Single Screw compressor units are low vibration machines. Under most conditions, no elaborate foundation is
necessary. However a sound foundation maintains motor alignment and proper elevation, and is therefore required.
Provided are recommendations for the foundation and anchoring of the compressor unit. The Vilter foundation sup-
ports the entire operating weight of the unit and is suitable for years of continuous duty. Included are specifi cations
for concrete, rebar, aggregate, anchors and grout.
Considerations Prior to Starting
Consult professionals, such as building inspectors, structural engineers, geotechnical engineers and/or construction
contractors prior to starting. Below are a few points to consider:
Site Characteristics:
• Soil information
• Site drainage
• Wind data
• Seismic zone
• Ingress and egress
• Power and power lines
Site Layout:
• Plant elevations, grading, drainage and erosion
• Accessibility to compressors for service
• Location of surrounding buildings
• Property lines and roadways
• Power
• Fire safety
Safety:
NOTE
Always check with a safety engineer before proceeding.
• Arranging equipment with adequate access space for safe operation and maintenance
• Wherever possible, arrange equipment to be served by crane. If not feasible, consider other handling methods
• Make all valves and devices safely accessible
• Use special bright primary color schemes to differentiate service lines
• Lightening protection for outdoor installations
• Relief valve venting
Foundation Materials
Materials needed to build the foundation are forms, concrete, sand, rebar, wire, grout, anchor bolts, expansion board
and shims. A set of concrete forms will need to be acquired; generally, these can be rented or constructed from
dimensional lumber. There should be enough 4,000 psi concrete with one inch aggregate to build the foundation.
Also, there should be enough sand to provide a base of compacted sand four inches thick for the foundation to rest
on, see Figure 1 - Concrete Pad with Compressor Unit Dimensions - Side View. The rebar required is ASTM 615, grade
60, sizes #4 and #6. Wires will also be needed to tie the rebar together. The recommended grout is Masterfl ow 648CP
high performance non-shirk grout to provide at least a 1” thick pad under each foot. The recommended anchors are
5/8” Diameter HILTI HAS SS threaded rod for outdoor installations or HAS-E rods for indoor installations. Anchor bolts
shall have a fi ve inch projection and 12-3/8” embedment. The required adhesive is HIT-ICE/HIT/HY 150 anchoring
system. There should be enough one inch expansion boards to go around the perimeter of the foundation. Finally
there should be enough shim stock and extra anchor bolt nuts to level the compressor unit.
