AB Series Spring-Flex Isolators with an elastomeric cup are designed to isolate low frequency vibrations in air handling units, fans, chillers, and other HVAC equipment. The AB Series are recommended for use directly under HVAC, power generation  and electrical equipment in conjunction with structural steel bases and concrete inertia blocks.

The AB Series are free standing and laterally stable spring isolators. The coils are designed with an excellent ratio between the coil outer diameter and operating height, ensuring lateral stability. In all of our designs, this ratio is a minimum of 0.80 and many of our springs have approximately a 1:1 ratio. In addition, our coils are designed with low operating stresses, thus ensuring a long operating life for the isolator. The AB Series also feature weldless construction. The spring coils are not welded to steel plates. Instead, the AB Series are assembled to elastomeric cups and steel plate bases with two mounting holes for attachment to structure - providing durability and flexibility. The series also include a built-in leveling device for simplified installation. The product incorporates a color-coded steel spring for ease of identification and inspection in the field. All of our open spring isolators have leveling capability and include a bolt hole in the bottom cup. They are available with deflections up to 2 inches.

Features & Benefits

  • Loads from 50-3,250 lbs. with static deflections up to 2” provide flexibility over a wide range of applications
  • Free-standing spring isolators offer a 1:1 lateral stability ratio
  • Built-in leveling device offers simplified installation
  • Weldless construction provides flexibility in replacing or interchanging springs
  • Color-coded springs provide easy identification of Spring-Flex isolators for installation and inspection


  • Air handling units
  • Fans
  • Pumps
  • Chillers
  • Air compressors
  • HVAC equipment
  • Power generation
  • Electrical transformers




The engineers we employ hold the highest industry-recognized credentials in structural analysis, elastomer development and system dynamics.


We are the first ISO accredited PCA ISO-17065, third-party certification body for special seismic certification of non-structural building components and their mounting configurations by the ICC’s International Accreditation Service.

Test & Measurement

We are the only ISO 17025:2005 Accredited Seismic Simulation Test Laboratory with a triaxial shake table owned and operated by California licensed Structural engineers.

Testing Services Update
DCL now offers Nuclear Qualification and Testing services.

In partnership with Greenberry Industrial, we now offer testing services that meet the requirements of ASME NQA-1.

Call for more information.