Cunningham​salesinc.

Seismic Engineering Index

Simple specifications for mountings used in seismic zones call for static g ratings in three planes. Welded and ductile spring designs such as the SSLR and SSLFH meet these requirements, as do the BR, RBA, RCA and RDA. The type M is a special design for bomb blast protection. Submittals include either static calculations or independent laboratory test data.

Seismic Engineering Index

The best approach to the seismic problem utilizes our Z-1011 snubbers designed with the proper response to a specific earthquake curve. The Z-1011 series have been tested and rated for stiffness and ultimate capacity. Air gaps between the AASHO bridge-bearing neoprene bushings and the steel housings prevent short circuiting of the isolation provided by the springs. Applications are normally backed up by our computer program as developed by the University of California in Pasadena. The dynamic program accepts the earthquake or bomb blast input and predicts motions and accelerations at the bearings, mechanical service connections and structural attachments. This enables us to maintain specified motion and deceleration levels. The Z-1225 is a simpler design primarily used when only static analysis is required.
 

Rubber Flexible Connector Index

Our designs include the threaded SFU thru 2”, the double sphere flanged SFDEJ thru 12”, as well as the single sphere SFEJ thru 24” diameter. These connectors are not wire reinforced; they are constructed of multiple plies of Kevlar tire cord and EPDM in a manufacturing process very similar to the manufacture of truck tires. This construction enables these connectors to breathe volumetrically and to be rated for maximum elongation so control rods are not necessary. We have been involved in intensive testing of these connectors through acoustical firms such as Cerami & Assoc., to verify that they are extremely effective in reducing both noise and vibration at pump impeller frequency (rpm times number of blades).

 We believe that we are the only firm that has developed this sort of acoustical data. The change to Kevlar, EPDM and captive flanges has virtually eliminated all failures.

Seismic Engineering Index

Our computer program analyzes spring and snubber systems under any given machine and responds with the natural frequency in all six modes.

Architectural Engineering Index

Vibration isolation technology has moved on to the isolation of entire buildings rather than just building components. We have designed and manufactured Neoprene and Natural Rubber bearing pads to frequencies as low as 6 Hz and steel spring assemblies in the 0.75 to 2.00 inch (19 to 50mm) deflection range in individual capacities of 1,000,000 lbs. (454,000 kgs.) Both techniques are used to keep ground vibration and noise out of buildings close to railroads, subways, heavy traffic or industrial impact.

Architectural Engineering Index

The idea of pouring a secondary floor on an elastic medium goes back as long as we can remember. Cork was the first material, but because of its high frequency early floating floors were not too effective. The method of pouring concrete on plywood supported by fiberglass was improved upon by substituting EAFM-AASHO bridge-bearing neoprene mounts for the glass. Panels are not the best approach, however, and we recommend the jack-up system. You pour the secondary floor around FS-1702 or FSN mounts on plastic sheeting spread over the sub floor. The cured slab is lifted by turning the adjustment bolts in each mount...

Spring Mounts Index

Helical spring mounts have been around for many years, but our company pioneered the use of springs designed with diameters equal to or approaching their operating height. The SLF configuration is used without housings for maximum vibration attenuation. While our telescoping Type C casting does introduce some damping, all of the other housings encase the spring without interfering with its action. The Type KIP and KIJ can be cast into foundations poured in place. The springs are adjusted to elevate the foundations...

Spring Mount Index

Helical spring mounts have been around for many years, but our company pioneered the use of springs designed with diameters equal to or approaching their operating height. The SLF configuration is used without housings for maximum vibration attenuation. While our telescoping Type C casting does introduce some damping, all of the other housings encase the spring without interfering with its action...

Neoprene Mounts and Pads Index

When we designed our ND mountings back in 1958, they were the first to have all metal parts covered by neoprene to prevent corrosion and to provide a nonskid surface. The ND was made taller to gain added deflection, rather than using the old technique of bolting two mountings in series. Individual neoprene mountings are available in load ranges from 15 to 4300 pounds per mounting. The BR, RBA, RCA & RDA mountings are captive designs suitable for mobile installations and applications in seismic zones. ML Mountings are used for machinery leveling.

Hanger and Piping Specialties Index

Resilient guiding and anchoring of piping has always been something of a problem. Many designs place the resilient material in direct contact with the piping surface. Since the materials are normally rubber or rubberlike, there have always been problems of heat sensitivity, friction and wear as the piping slides against the resilient surface. In some cases, there was also an unpleasant odor, as these materials tend to smell when heated...

Hanger and Piping Specialties Index

Primitive forms of neoprene hangers (HD), spring hangers (HS) and combination spring and neoprene hangers (DNHS) were around before 1958, but we improved them all as we established our standards. Our most sophisticated design is the 30N, which uses a spring series even larger in diameter than those used for the SLF mountings. This enables us to enlarge the hole in the bottom of the hanger box so the suspension rods can swing through a full 30 degree arc, virtually eliminating the age-old problem of hanger rods rubbing against the holes in the hanger boxes and short-circuiting the system...
 

Hanger and Piping Specialties Index

Cable braces are the most efficient means of keeping suspended equipment, electrical conduits, piping and duct work in place during earthquakes or bomb blast. There are many requirements for the best and quickest means of connection so we have developed a wide range of products in various capacities. All are California OSHPD approved or in the approval process. Our cable products are hinged to adjust to the installation angle and avoid cable fraying...

Bases and Rails

Type WFSL, KSL, and BMK bases have become industry standards because we have encouraged specifications calling for structural steel perimeters with a depth equal to 1/10th the length for WFSL frames and 1/12th the length for the concrete filled BMK and KSL designs. Height saving brackets are almost always used and bases are customized to fit 1-1/2 HP close coupled pumps all the way up to 8000 ton centrifugal machines, with a variety of fan, pump, compressor, chiller, etc., base designs in between.

Roof Curbs Overview

Bases and Rails

The CMAB aluminum standard curb spring cap has been largely superceded by the RSC design. This complete rooftop spring curb is supplied in standard deflections up to 3” and as much as 5” in special designs. Springs are adjustable and removable...