Certifications · Compliance · U.S. DOT
DOT Special Permits
Welker products are authorized under U.S. Department of Transportation Special Permits for the transportation of hazardous materials in pressure vessels. Search by product, MAOP, or permit number.
CP-2 (50 cc – 1,000 cc)
Piston style receptacle has flat heads on each end restrained with tie rods secured at each end by nuts or with tie rods threaded into an end cap and secured by nuts on the other end. The maximum volume may not exceed 1,000 cc.
View Permit (PDF) →CP-4 (15 cc – 100 cc)
Piston style receptacle has threaded flat end caps on each end without tie rods. The maximum volume may not exceed 100 cc.
View Permit (PDF) →CP-5 (Piston)
Piston style receptacle has flat heads on each end restrained with 8-5/8 inch tie rods which are secured by nuts. The maximum volume may not exceed 6,000 cc.
View Permit (PDF) →CP-5 (Single)
Single cavity receptacle (without pistons) has flat heads on each end restrained with 8-5/8 inch tie rods which are secured by nuts. The receptacle has an eight bolt configuration. The maximum volume may not exceed 6,000 cc.
View Permit (PDF) →CP-2HP (Single)
Piston style receptacle has flat heads on each end restrained with 6-1/2 inch tie rods which are secured by nuts at one end and threaded into the flat head at the other end. The maximum volume may not exceed 1,000 cc.
View Permit (PDF) →CSCC
OverPak Core Carrier will hold two different sensorwise coring tools.
View Permit (PDF) →CP-24GA
Piston style receptacle has flat heads on each end restrained with 6-1/2 inch tie rods which are secured by nuts at one end and threaded into the flat head at the other end. The maximum volume may not exceed 1,000 cubic inches.
View Permit (PDF) →CP-35
Piston style receptacle has flat heads on each end restrained with tie rods secured at each end by nuts or with tie rods threaded into an end cap and secured by nuts on the other end. The maximum volume may not exceed 1,000 cc.
View Permit (PDF) →TCC Optimum™
Pressure vessel constructed of SA-240 316L stainless steel. The maximum capacity is 2.5 gallons.
View Permit (PDF) →Try a model (CP-5), a pressure (2,160), or a permit number (11054), or set the permit to All. Still can’t find it? Call 281.491.2331 or email sales@welker.com.
Understanding DOT Special Permits
What Is a DOT Special Permit?
A DOT Special Permit authorizes a company to transport hazardous materials in a manner that varies from federal regulations, subject to conditions that provide an equivalent level of safety. Welker sample cylinders and containers are authorized under the permits below.
Equivalent Level of Safety
Each permit sets the design, construction, and use conditions a container must meet to ship hazardous materials safely.
MAOP
Maximum Allowable Operating Pressure. Each product’s MAOP is defined within its Special Permit and must not be exceeded during transport or operation.
Verified by PHMSA
Every permit links directly to the official PHMSA (Pipeline and Hazardous Materials Safety Administration) database for verification.
Official Documents
Welker DOT Special Permits
Open the current permit document directly from PHMSA.
DOT-SP 7657
2 Welker products authorized under this permit.
View on PHMSA →DOT-SP 11054
5 Welker products authorized under this permit.
View on PHMSA →DOT-SP 10370
1 Welker product authorized under this permit.
View on PHMSA →DOT-SP 16074
1 Welker product authorized under this permit.
View on PHMSA →Find More Welker Documentation
Certifications & Compliance
ISO, CRN, CSA, DOT, and Transport Canada certification and compliance documentation.
View Certifications →CRN Registrations
Canadian Registration Numbers for Welker pressure equipment, searchable by province.
View CRNs →IOM Manuals
Installation, Operation & Maintenance manuals for Welker products, current and legacy.
View IOM Manuals →Technical Papers
Technical papers and publications authored by Welker engineers.
Read Papers →Case Studies
See the systems Welker is delivering in the field — LPG, flare gas, refined products, and more.
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Browse Resources →Questions About DOT Compliance?
Our team can help you verify that your Welker equipment meets all applicable DOT transportation requirements for your application.
