Fronek Anchor/Darling Enterprises, a division of PT&P designed and fabricated hydraulic snubbers for a geothermal facility in California. The Fig. 510 AD snubbers ranged in size from 34-3/4″ to 37-5/8″ piston-to-piston and were designed for a 50,000 lb. maximum load, 5″ cylinder size and a 6″ stroke. The Fig. 511 AD snubbers ranged in size from 56-15/16″ to 59-5/16″ P-P and were designed for a 20,000 lb. maximum load, 2-1/2″ cylinder size and a 6″ stroke. Hydraulic snubbers are designed to protect the piping system when a sudden, heavy load is applied (such as an earthquake of high intensity), which can cause serious vibrations leading to complete destruction. A custom three-bolt pipe clamp fabricated from carbon steel was designed to fit in a limited space. A cycle test throughout the full stroke from zero to fully extended was performed prior to shipment.
Follow these 7 steps below to maintain and extend the life span of your hydraulic snubber.
Hydraulic Snubber Assembly
1. Observe the fluid level to make sure there is sufficient fluid for the snubber to operate
2. Check for leaks – If the fluid level is decreasing, determine the cause and effect remedial action.
3. Check the condition of the load pins and spherical ball bushings. Apply a high pressure grease for long-term benefits.
4. Check the condition of the exposed portion of the piston rod. Check for scoring, paint or other physical damage.
5. Check the condition of the piston rod wiper. Verify that it’s in position and working effectively.
6. Check for evidence of abuse like welding arc strikes, bent or dented parts, scratched paint, etc.
7. Finally, check the overall physical appearance. This encompasses all of the above.
A total of eight big ton spring supports, “mega tons” were designed and manufactured to support two reactors in a power plant weighing approximately three million pounds each. The mega ton pictured incorporated eighteen individual spring coils to produce a load capacity of approximately 602,000 lb. and a spring rate of 112,500 lb./in. It was designed with eight Bronzphite® slide plates that measured 12″ x 12″. The 12″ x 12″ slide plate selection was based upon the ability to position individual squares across the load flange surface while simultaneously providing the total slide plate surface area required to support the operating loads.
By using individual slide plate squares, the fabrication and assembly time was reduced because a standardized mounting procedure could be incorporated and repeated as necessary for each big-ton load flange subassembly. Overall, the slide plates were incorporated into the design to reduce the horizontal forces which would be imparted onto the big-ton spring’s load flange during lateral deflection (movement) of the reactor.
Bronzphite® slide plates, in particular, were selected because these big-tons will be used in a location which will see continuous “cold-to-hot” operating cycles and as a result, the robust nature of Bronzphite® proved more advantageous than other types of slide plates. The other two designs used nine slide plates, one with fifteen individual coils to produce a operating load of 594,000 lb. and a spring rate of 250,050 lb./in. The other design had an operating load of 300,000 lb. and a spring rate of 106,000 lb./in.
These F-type variable spring supports are fabricated from carbon steel with a hot dipped galvanized finish and designed with guided load columns to provide stability for minimum lateral movement. The fig. 46 pipe saddles are also fabricated from carbon steel with a HDG finish and lined with PTFE, 25% glass filled material. The pipe saddles are designed for 8″ to 36″ diameter pipe sizes, and the entire assembly is 50″ in height. These variable-saddle support assemblies are capable of supporting up to 22,300 lb. and 1″ vertical movements. We performed standard spring loading tests and a Q.C. inspection prior to shipping to an offshore oil and gas platform near Malaysia.