Industry and case studies from practice

A Top Separator in a Kamyr Digester of a Pulp Mill was packed with a Graphite Fiber Packing. It was operating at 160° C / 320° F and 16 bar / 230 psi. The packing had a X-Section of 19 mm / 3/4" and 7 rings sealed Wood Chips and Liquor on a 220 mm / 8.66" shaft. A lantern ring was not installed, therefore causing no dilution. Previous packing damaged the shaft sleeve. The old packing was always hard to remove and costing extra maintenance time. The run in was always a long procedure. The service time of the previous packing was 2 months. With TrapezPack^®30 it was a fast approach to get the required drip rate. It kept running at the desired drip rate for 1 week without any further adjustment. After outperforming previous packing 3-fold it is still in service.

In the recovery area of the powerhouse of a Pulp mill a Graphite packing was used to seal Green Liquor with a pH 12 on a slaker tank agitator. The operating pressure of 1 bar / 14.5 psi was sealed with 6 rings of a 12.7 mm / ½" packing running with 30 RPM on a 114 mm / 4.5" shaft at 105° C / 210° F. The setup was flushed through a lantern ring.

Previous packing was graphite with a High-tech Plastic Compound Bushing.  The packing was being abraded away as the bushing would trap the green liquor in the packing. Its service time was 6 months. The replacing packing was Trapez-Pack^® 30 supplied as die formed rings. It has run flawlessly from annual shutdown to annual shutdown, 12 months.

In a sugar factory, a ParaAramid packing was used in a Warman 10/8M pump to seal sugar juice. The operating data were 1400RPM, 4 bar and 70°C product temperature. The previous service life was 2 weeks. The product contaminated the pump environment by uncontrollable leakage and also penetrated the bearing housing. Carbon fiber/PTFE packing TP30 was installed, and the pump ran through the entire campaign with controllable drip leakage.

At a sugar manufacturer a diffusion tower needed to be sealed. It had a 500mm shaft which turned at 8 RPM. The packing had a dimension of 25mm, 5 rings have been installed. In use was a PTFE/Graphite Packing which was ParaAramid corner reinforced. Service time was 2 weeks. The customer reported that it destroyed the shaft sleeve and since the leakage was not controllable the bearing arrangement was damaged too, and the repair cost have been enormous. TP30 was chosen as a replacement and the customer reported that he can easily maintain the required drip rate and has it still installed after 3 months of service.

In a coal-fired power plant, a Clyde Bergemann sootblower was previously sealed with a graphite packing. The product to be sealed was steam. 7 rings with the dimension 60x80x10mm were installed. The usual service life was 6-9 months. The packing had to be retightened weekly, in some cases by half a turn on the eyeglass bolts. To improve the service life, the SOOTSTAR carbon black blower set was used together with the LiveLoading System Proload. The service life was 15 months. Leakage was not visible and the need for adjustment was one eighth of a turn per month and was indicated by the ProLoad system.

In a coal-fired power plant, a Clyde Bergemann carbon black blower was previously installed with a graphite packing set consisting of braided graphite pre-bearing rings and graphite foil rings divided into half shells. The product to be sealed was steam. A total of 7 rings measuring 60x80x10mm were installed. In order to keep the plant running, one ring had to be refilled every week. To improve the service life, the SOOTSTAR carbon black blower set was used together with the LiveLoading System Proload. The service life was 12 months.

In a coal-fired power plant, a Mitsubishi sootblower was previously installed with a wire-reinforced braided graphite packing. The product to be sealed was steam. A total of 9 rings measuring 60x75x7.5mm were installed. The service life was 2 months. For optimization, the SOOTSTAR carbon black blower set was used together with the LiveLoading System Proload. The service life was 14 months, and the application showed no visible leakage.

In a chemical factory, a water/steam mixture was sealed in a dryer. The speed of the 834 mm shaft was very low at 6 rpm. The pressure, on the other hand, was very high at 15 bar and 250 °C temperature. 8 rings of a 25 mm packing were used. The previous packing lasted 6 months. Repacking was a costly affair due to the cooling process of the line and also involved product loss in addition to the downtime costs. The TP55 was chosen as an improvement. It lasted 24 months so far.

In a chemical factory, PTFE/graphite packing was previously used to seal gypsum slurry with phosphoric acid at ambient temperature. The pump had a 65 mm shaft with a speed of 1450 and delivered 4 bar. 5 rings of a 16mm packing were installed. The service life so far was 1 week. The packing hardened badly and sometimes damaged the protective sleeve very badly. A TP30 was chosen as a replacement. It was much easier to break in. The desired drip rate was achieved quickly and remained constant for much longer. The service life extension was over 4 times that of the previous packing.

In an iron ore mine, iron ore rock and slurry with a pH of 10 had to be sealed in a Warman pump. The speed of the 178mm / 7.00 shaft was 900 rpm. Pressure 6 bar / 85 psi at ambient temperature Sealing was done with a 25mm / 1” standard glass PTFE packing and 4 rings and had a service life of 2 weeks. The reason for failure was uncontrollable leakage. The shaft sleeve was heavily worn by the packing used. The packing was very difficult to remove, and this cost extra assembly time. The P9Blue was used as Upgrade. It retracted quickly and held the required drip rate for 1 week without further adjustments. The service life exceeded 3 times that of the previous installation.

In a waterworks, a pump with a 50mm / 2.0" shaft and a speed of 500rpm had to be sealed against 1 bar / 14 psi pressure and ambient temperature in the wastewater area. After only 2 days, the installation showed increased leakage and failed after 2 weeks due to extrusion and the fact that the gland could not be adjusted anymore. The P1X was supplied as a replacement. She proved itself with a service life of 6 months.

In a food processing plant, 4 rings of dry PTFE packing in 12.7 mm on a 30 mm shaft were installed in an Isegen rotary valve. The pressure was low and was only 1 bar. The food to be sealed was at room temperature. The service life of the packing was mostly only 2 weeks and ended with an uncontrollable leakage. The shaft sleeve used had to be replaced after 12 months. The TP619 was chosen as an improvement. It has lasted 6 months so far.

At a shipyard, pumps supplying the dry dock were sealed with 4 rings of 22 mm packing. Previously, expanded graphite packing was used. It tended to run hot and the product crystallized, damaging the shaft sleeve. The product was seawater with a pH value of 8 and ambient temperature. The pressure was 1 bar. The service life reached only 1 month. The customer was looking for a solution that lasts longer would not cause damage to the shaft sleeve. The TP18 was chosen. It lasted 4 months and tread was perfect.

In an oil refinery, an asphalt/heavy-oil loading pump with a 50mm shaft was sealed by 7 rings of 14mm packing. The product temperature was 135 °C and the pressure was 12bar. The speed of the shaft was 720 rpm_-1. So far, a PTFE/graphite packing was used. It had to be retightened weekly and the maximum service life achieved was 3 months. A TP30 packing supplied in pre-compressed rings was used as an improvement. It lasted 12 months and had to be retightened only 1 time per month.

In an oil refinery, a fire department pump was sealed against seawater at ambient temperature and 10 bar pressure. The pH value was close to neutral. The speed was 2900 rpm. The shaft had a diameter of 37.5 mm and 5 rings of 8 mm packing were used. When the system pressure dropped, the pump started automatically and charged the system to the required pressure level. This resulted in dry running at the beginning of the pumping time. This happened 15-20 times a day. The installed PTFE packing with inlet lubricant burned and damaged the shaft. The service life was only 2 months. The new installation used D3.5 pre-bearing rings, which protect a P1P packing against extrusion and abrasive materials. The service life achieved was 36 months.