STRENGTH

Independently tested by a U.S. facility, Pamrex is capable of withstanding an average load of 120,000 lbs.  This much greater than the AASHTO H20 heavy duty loading.

DUCTILE IRON

The key to Pamrex's  strength is ductile iron.  Ductile iron provides a superior strength-to-weight ratio, which allows up to a 50% weight savings compared to cast-iron designs.  For more detailed technical information on the properties of ductile iron, click here.


PAMREX DESIGN FEATURES

  • Improved ergonomics:
    • Hinges reduce the physical effort by 50%.
    • Hinges allow operator to move in a straight line, thereby avoiding damaging spinal rotation.
    • Hinges minimize the duration of the lift; the hinge also retains the cover in a safe and controlled way during and after the lift.
    • Lifting points in the cover are designed for use with standard tools (pickaxe/hook/bar).
  • Hinge incorporates a 90º blocking feature to prevent accidental closure.
  • Self-centering design of the gasket eliminates the need to guide the cover into position when closing.
  • Design of apertures ensures easy insertion and removal of tools.
  • Lifting loops in the frame facilitate safe offloading and installation with the proper equipment.
  • The cover is designed to open and release pressure if the sewer becomes surcharged. 
  • The cover can be removed if necessary.

STABILITY AND DURABILITY

Elastomer gasket shown in red

Elastomer gasket shown in red

Elastomer gasket rings absorb damaging traffic shock and help to prevent the breakdown of frame and bedding materials.  Therefore, structural failure that can lead to more serious problems like frame instability is significantly reduced.  Scientific analysis has clearly show that new gaskets absorb 64% of the shock, and even after many years of service continue to absorb over 50% of the shock.  The elastomer gasket ring in the Pamrex manhole cover ensures stability, regardless of traffic conditions.

INFILTRATION

Pamrex dramatically reduces the amount of surface water entering the sewer system.  Testing has shown a reduction in infiltration down to less than 0.3g/hr.  In addition to the elastomer gasket,  Pamrex covers feature an innovative plug for the hinge housing to achieve this level or water resistance.  The dual wiper plug reduces the amount of water entering the network while at the same time enabling debris to be easily removed from the hinge housing.

SECURITY

Pamrex manhole covers can be fitted with a specially designed locking assembly to increase resistance to unauthorized access.  On-site installation of retrofit locking assemblies generally takes no more than five minutes.

QUALITY ASSURANCE

The Pamrex manhole cover unit has been designed and manufactured within a certified ISO 9000 quality management system, certified by an independent, internationally recognized third party.  Production incorporates regular testing of the material and final product including extensive field testing and heavy traffic situations.

For more detailed information on the testing that all PAM covers are subjected to, click here.

PAMREX SIZING

  • PAMREX 24":  designed to cope with any kind of traffic but remains quiet thanks to its elastomer gasket.  Pamrex is a reliable manhole cover that has withstood the test of time.
    • Opens to 130º, blocks at 90º when closing, elastomer gasket, H20 load rated, infiltration plug, single hinge, lifting loops integral to frame, locking devices available, retrofit badge.

  • PAMREX 28":  has the same functional features as the Pamrex 24", access is made through a wide 28" clear opening specially designed for systems requiring special safety conditions for operators.
    • Opens to 130º, blocks at 90º when closing, elastomer gasket, H20 load rated, infiltration plug, single hinge, lifting loops integral to frame, locking devices available, retrofit badge.

  • PAMREX 32":  provides easy opening, while continuing to offer the high performance levels of the successful Pamrex 24" and 28" clear opening designs.  The 32" clear opening enables maintenance personnel to enter the manhole with their safety equipment, or to lower bulky equipment into the below-ground network.
    • Opens to 130º, blocks at 90º when closing, elastomer gasket, H20 load rated, infiltration plug, double hinge, lifting loops integral to frame, locking devices available, retrofit badge.

  • PAMREX 36":  designed to enable easy access to large manhole openings, the newest Pamrex unit features a unique dual-hinge design and gas arm strut.  Manufactured from high-strength lightweight ductile iron, the unit maintains all the performance levels you've come to expect from the original Pamrex range.  The dramatic reduction in weight as compared to traditional cast iron, and the easy handling provided by this design, finally solves the access problem faced by utility operators and maintenance personnel, who would ordinarily required specialty equipment to open and enter large manholes.  Easy access is provided by the wide 36" clear opening.
    • High strength, ergonomic advantage, safe, infiltration resistant, silent, stable, locking device standard, retrofit badge

Pamrex Specification

  • PAMREX or similar approved Manhole Frame and Cover.
  • Covers and Frames shall be manufactured from Ductile Iron in accordance with ISO 1083.
  • Covers shall be one-man operable using standard tools and shall be capable of withstanding an average load of 120,000 lbs.
  • Covers to be hinged and incorporate a 90º blocking system to prevent accidental closure
  • Frames shall be circular and shall incorporate a seating gasket; frame depth not to exceed 4" (24" and 28") or 5" (32") or 6" (36")
  • Frames shall be complete with dual wiper infiltration resistant hinge plugs
  • The flanges shall incorporate bedding slots and bolt holes
  • All components shall be black coated*
    • *The components can also be in epoxy
  • Product shall be manufactured in ISO 9000 certified manufacturing plants