Skirt, Bracket & Ring Supports

Roben, Mfg., Inc. specializes in the custom engineering and fabrication of skirt, brackets or ring support for chemical, fine chemical, petrochemical, pharmaceutical, food and beverage, defense, and power-generation industries. Every project is designed to ASME Section VIII Division 1 (with optional Division 2), is National Board registered, complies with the European Pressure Equipment Directive (PED 2014/68/EU) for CE marking, and is registered under the Canadian Registration Number (CRN) system for all Canadian provinces.

What Skirt, Brackets or Ring Support Are

Skirt, bracket, and ring supports are the structural elements that transfer the weight, wind, and seismic loads of a column or vessel into its foundation or supporting steel. Skirt supports are continuous cylindrical shells welded to the bottom head; bracket (lug) supports are localized lugs welded to the shell; ring supports are continuous rings carried on a structural steel framework.

Why Skirt, Brackets or Ring Support Matter

The support type is one of the most consequential decisions in column engineering. It depends on the column's height, weight, operating temperature (which drives differential thermal expansion), foundation type, and seismic/wind environment. The wrong support choice can cause cracking, foundation overload, or installation difficulties.

Skirt, Brackets or Ring Support — Specifications and Capabilities

Skirt: Continuous cylinder, 1/2 in. to 4 in. thick, with anchor bolt chairs, vent slots, fireproofing as required

Bracket / lug: Localized lugs welded to the shell, sized to AISC and ASME UG-22

Ring support: Continuous ring on structural steel — common for short, wide vessels

Materials: Same as the vessel shell, or carbon steel with refractory lining for hot service

Anchor bolts: 1 in. to 4 in. diameter, ASTM F1554 or equivalent

Certifications and Codes

ASME Section VIII Division 1 — U-stamp

ASME Section VIII Division 2 — available on request

National Board registration — R-stamp

PED 2014/68/EU — CE marking with Notified Body coordination

CRN — registered for all Canadian provinces

NACE MR0175 / ISO 15156 — sour-service compliance

AWS D1.1 / ASME Section IX — qualified welding procedures and welders

Frequently Asked Questions About Skirt, Brackets or Ring Support

When should I specify a skirt support vs. lug support for a column?

Tall columns (height/diameter > 5) are almost always supported by a skirt — it provides better wind/seismic stability and uniform load transfer. Short, smaller-diameter vessels can use lug or bracket supports. Lugs are also used when foundation cost is to be minimized.

How is the skirt designed to handle differential thermal expansion?

For hot-service columns, the skirt is designed with vent slots, an insulated transition zone, and sometimes a hot-box to prevent thermal-bowing and cracking at the skirt-to-head junction. We perform thermal-stress FEA when needed.

What are anchor bolt chairs and why do they matter?

Anchor bolt chairs distribute the bolt tension into the skirt without concentrating stress at the bolt holes. They consist of a top plate, a gusset, and the embedded bolt — designed per AISC and ASME criteria.

Does Roben Mfg. design the foundation?

We design the support and provide the loads (vertical, base shear, overturning moment, anchor bolt forces) to the foundation engineer. The civil engineer designs the concrete pad and embedment.

Are skirt supports fireproofed?

Yes — skirts in hydrocarbon service are typically fireproofed (cementitious or intumescent coating) to maintain structural capacity for 1.5 to 4 hours during a fire event, per the project's fire-protection specification.

Request a Quote on This Project

Contact Roben Mfg., Inc. to discuss your project specifications, timeline, and material requirements.

📞 (732) 364-6000 ✉ sales@robenmfg.com 📍 760 Vassar Ave, Lakewood, NJ 08701

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Skirt, Bracket, and Ring Support for Columns