Sometimes the differential pressure is higher than normally designed differential pressure, thus indicating a higher flowrate than designed; as noted it could result in inefficient performance or a malfunction. Often the differential pressure is lower than the designed value, which could be as a result of wear in the inner labyrinth seal. When using the product as a sealant, make sure that application results in a good bond between Dry Seal MP and the substrate. The operation range of seal system instruments: The instrumentation and control systems for sealing systems vary per application. In some of these applications, instruments or valves might be improperly specified. Sometimes the instrument range is not sufficient, and too often seal system flowmeters are not sized properly. In a case study for a turbocompressor, the original seal filter meshing was 4 microns. The upgraded seal filter was a filter system with the 1 micron mesh size and the dimensions 2.5 times larger than the original filter. At Dry Seals we have harnessed this technology by creating a series of cured silicone extrusions that we call Dry Seals.

Lubrication oil is another important root-cause of seal failures. The first section that will be contaminated by lubrication oil is the barrier seal (the separation seal). For such cases, there will be oil ingress past the barrier seal. The second section that will be contaminated is the secondary seal. If the lubrication oil can pass through barrier seal and contaminate the secondary seal, the secondary seal may fail, leading to problems with the primary seal (oil ingestion and subsequent failure). Seal system improvements However, where sprayed, items such as windows and surfaces which are (or will be) varnished or painted, as well as plants, should be covered with Polythene Sheets. Our Glass Protection Film is ideal use on windows.

Figure 2. An example of a 3D model of a modern dry gas seal. The dry gas seal details are shown in this 3D model. Finding a sealing element that guarantees sealing without leaks and adds durability to applications of this type poses a difficult challenge. The inner labyrinth seal (or process labyrinth seal) plays an important role in the performance and reliability of a turbocompressor and its dry gas seals. The differential pressure across the inner labyrinth seal should be carefully monitored. This differential pressure needs to be maintained at a relatively constant designed value for uninterrupted and stable flow. A low seal gas flow (to process side) may cause migration of dirty process gas into the seal. A high flow may cause the flow coefficient in the system to exceed the designed value, creating detrimental flow turbulence, as well as inefficient performance. A minimum shaft speed is required for the operation of dry gas seals. This speed is known as the lift-off speed. Care should be taken for variable-speed turbocompressor operation (particularly steam turbine- and gas turbine-driven compressors) to ensure the operation is always above the specified minimum speed for the dry gas seals. Steam turbine- and gas turbine-driven compressors usually require cool-down operation at low speed after a shutdown and this low speed rotation should be performed with respect to the specified minimum speed for the dry gas seals. Historically, many dry gas seals have been damaged in low-speed operations. Seal gas booster: A commonly reported root-cause for seal failures has been low pressure of seal gas at startup, which resulted in dirty gas moving to the dry gas seal from the compressor casing. It is recommended to install seal gas boosters to ensure supply of seal gas during standstill and transient conditions, if a reliable source of seal gas with suitable conditions is not available for these transient times (particularly the startup).

With its unique thixotropic consistency and excellent water repellent properties on a range of building materials, Dryseal Masonry Waterproofing Cream stands out. The first dry gas seal for a compressor was patented by Kaydon Ring & Seal in 1951 when it was known as Koppers Corporation. Field applications of dry gas seal designs were completed in 1952. The original patent was for Kaydon's "Tapered Ramp" lift geometry, a constant diameter / variable depth dynamic lift design. From that first dry gas seal ever manufactured for a centrifugal compressor in 1951, Kaydon Ring & Seal has been instrumental in developing the dry gas seal into one of the most reliable and maintenance free sealing solution available today. One solution might be the double mounting of mechanical seals that provide the necessary lubrication, provided they are compatible with the product, which is not always possible.The separation seal is installed between the compressor bearing and the secondary dry gas seal. The separation gas system function (the barrier seal system function) prevents lubrication oil from entering the dry gas seal. The nitrogen flow into the separation seal should be properly monitored. In many machines, the nitrogen supply system (such as control valves, control setting, etc.) does not receive proper attention, which could eventually result in seal problems and even seal failures. A low flow of nitrogen through the separation seal may allow the bearing lubrication oil to migrate into the seal chamber, causing seal face failure. A low flow of nitrogen is sometimes the product of an inaccurate setting of control valves on the nitrogen seal supply line. Dry gas seal root cause analysis To eliminate many of the problems noted above, there are some dry gas seal upgrades that can improve the reliability of turbocompressors. This effect should not be confused with the "beading" effect often associated with water repellents. The RCA (root-cause analysis) is an important step after a seal failure. After a dry gas seal failure, the seal should be sent to the seal manufacturer’s facility for dismantling and investigation.