Gland Packing Research Articles

Characteristics of packing gland seals in hydraulic systems of quarry excavators and results of comparative analysis of experimental tests

The efficiency of quarry hydraulic excavators will depend on several factors, namely the climatic conditions of the area where hydraulic excavators are used, the degree of air pollution (pollination), the performance of the structural parts of the excavator, the reliability of the hydraulic system, the performance and cleanliness of the hydraulic working fluid. In this area, research was carried out on the performance of seals used in the hydraulic system of quarry excavators. The article presents the results of experimental tests of the existing type of oil seal a and b, as well as the proposed oil seal type c, shown in Fig. 1.

원전용 밸브 패킹응력 해석을 위한 모델링 연구

The valve used in nuclear power plant must be qualified by the known experimental equation, which is the requirement of ASME QME-1 standard. Up to now, the stress on packing is assumed to be constant in design and experimental analysis. This paper deals with the development of analysis model for the packing stress. In the analysis model, the stress is calculated with the love function, whose eigen function is deduced by applying the separation method of axial and radial variables to biharmonic equation with boundary conditions. And the unkown parameters of love function are calculated by applying the remaining boundary conditions. The distribution of radial and axial stress are not constant and the big variation of stress is found at the inner and outer face. The radial stress after boundary layer of radial stress is 45% of gland packing stress. Considering the discussion that the double packing stress makes the radial stress in the packing as same as the fluid pressure, it is proper that the industrial design guide has been used to select the gland packing stress as twice as much as fluid pressure. And the force on stem can be calculated by applying shear stress of packing on stem area. Later, the load factor, which is used in the experimental analysis for consideration of stress distribution, must be related to the real stress distribution by this research result.

Beban Lebih Elektro Motor Pompa Ejektor Pada Fresh Water Generator di Atas Kapal Motor Penumpang Mutiara Ferindo II

The ejector pump has two main components, namely the electro-motor part and the mechanical part. The electro motor plays a vital role in the activity of draining sea water to the fresh water generator. The electro motor acts as a rotary driver in pump mechanics which has the working principle of converting electrical energy into mechanical energy. Control system and electro protection. The purpose of this research is to determine the cause of overload on a mechanical motor pump. The research was conducted by observation, namely direct observation of the pump which functions as an auxiliary machine. The results show that because the bearings experience excessive heat due to the connection at the center of the motor with the pump not being centered. Gland packing experiencing high speed events so that the shaft is difficult to rotate.

AES India invests in green technology

Aesseal Plc, a specialist in the design and manufacture of mechanical seals, bearing protectors, seal support systems and gland packing, says that its operation, based in Pune, India, is investing in green technology.

Deployment of a bioabsorbable plate as the rigid buttress for skull base repair after endoscopic pituitary surgery.

Bioresorbable alloplastic implants have become desirable as a rigid buttress for reconstructing skull base defects. This study aimed to describe the use of a biodegradable plate (PolyMax RAPID) in skull base repair of endoscopic endonasal pituitary surgery and to investigate the clinical outcome and safety of this novel method. Between January 2019 and January 2020, 22 patients with pituitary adenomas who underwent endoscopic skull base repair with a Polymax RAPID plate were included. After endonasal transsphenoidal surgery, a trimmed bioresorbable plate was placed in the position between the dura and the bone of the skull base to reconstruct the sellar floor and buttress the pituitary gland and sellar packing. The patient demographics, radiologic imaging, and postoperative outcomes were carefully reviewed. All patients were followed up by a routine nasal endoscopic assessment and radiologic examinations. The present study comprised 10 (45.5%) males and 12 (54.4%) females with an average age of 51.9 years. There were 7 (31.8%) growth hormone (GH) secreting adenomas, 2 (9.1%) thyroid stimulating hormone (TSH) secreting adenomas, and 13 (59.1%) non-functioning adenomas. Enlarged sellar floor and paranasal sinusitis were seen in 13 (59.1%) and 11 (50.0%) cases shown by preoperative computed tomography (CT) or magnetic resonance imaging (MRI), respectively. There were 6 (27.3%) grade-1 and 16 (72.7%) grade-0 cases by intraoperative cerebrospinal fluid (CSF) leak grading. None of these patients received lumbar drains postoperatively and no postoperative CSF rhinorrhea was detected in our series. The PolyMax RAPID plates which could be clearly identified on postoperative CT or sagittal T1-weighted MRI were shown to provide an ideal rigid buttress for sellar repair. The Polymax RAPID plate can be an optimal implant to achieve rigid repair of sellar floor defects after endonasal transsphenoidal pituitary surgery.

Design and Finite Element Analysis of composite PTFE Compression Packing with C-shape Structure

Gland packing is a sealing device in mechanical equipment like pumps. With the development of science and technology, new materials and new structures have appeared, giving new vitality and advancement to the packing seal. In the process of pump operation, the major problems of gland packing seals are the wear of the filler material and leakage of media through the interface. Hence, In order to improve the sealing performance of a gland packing, Different factors including design structure, the number of packing rings, type of filler material, operating condition like temperature, pressure and speed of shaft can be considered. In this study the finite element analysis of the packing seal is carried out, and the axial stress distribution, bottom pressure and friction moment of the packing seal are obtained according to its design structure and stress condition. Furthermore, the results of finite element analysis are verified by experiments.

Failure Analysis and Salvaging of Bellow-Sealed Sodium Valve

Valves with conventional gland packing seals are not suitable in high-temperature sodium systems. Bellow-sealed valves are used in sodium systems in which bellows are used as primary leak tight barrier. Bellows are made up of very thin gauge material, and hence, most of the failures in the bellow-sealed valves are due to failure of the bellows. The cost of the bellows is typically < 20% of overall cost of the valve. This paper discusses the failure analysis of the bellows in a failed bellow-sealed sodium valve and reconditioning of the same by replacing the failed bellow with new and improved bellows. Initially, sticking sodium from the internal surfaces of the valve was cleaned using alcohol. Subsequently, the failed bellows were disassembled from the valve and a detailed failure analysis was carried out. New and improved bellows were designed initially as per Expansion Joint Manufacturer’s Association (EJMA). The geometry arrived as per EJMA was further analyzed using visco-plastic constitutive model to obtain the creep–fatigue life of the bellows. The inputs from the failure analysis were considered while evolving the new and improved design of the bellows. The bellows were tested and qualified at high temperature and installed in the bellow-sealed valve. Integral testing of the valve was carried out using pressure hold testing and helium leak testing. The valve was reconditioned for further use in sodium services.

Fluid Thermal Effect on Non-contacting Labyrinth Seal of 20 MW Steam Turbine

This paper is divided into two parts; the first describes a CFD analysis of a gland packing labyrinth seals in 20 MW steam turbine in LNG plant using ANSYS CFX code as an isothermal simulation in fluid domain. The results of two turbulence models k-ε and k-ω SST are compared and validated against experimental data. It is shown that the labyrinth seal leakage is proportional to the clearance cube so any variation in clearance can have a significant impact on the steam leakage. This clearance between the shaft and the labyrinth seal vary as a function of operating temperature due to the different rates of thermal expansion of the materials for these two components. Likewise the fluid temperature has a direct effect on fluid dynamic behavior. For that; the second part of the paper investigates the effect of fluid thermal conditions of the labyrinth seal via the heat transfer and Nusselt number variation in the stator and the rotor, for different cases of inlet temperature (400 °C, 200 °C, 100 °C, 50 °C) and pressure ratio (2.5, 4.5, 6.5) for an ideal gas. Also it is important to know the temperature distribution across tooth and cavities of the labyrinth seal, and finally the Influence of Inlet total temperature on fluid pressure drop in the labyrinth seal will be treated for improving and readjusting the steam turbine sealing system.

Evaluation of the effect on sealing performance by the gland packing compression procedure

Evaluation of the effect on sealing performance by the gland packing compression procedure

The Problems of Measuring Profile and Roughness of Turbine Blades

The article presents a study of a turbine blade profile and roughness measurement processes - the task facing any manufacturer of this part. The blade is one of the most complex regarding parts manufacture because of its complex profile. This profile should be measured in several sections on the feather on all profile elements - the suction side, pressure surface, leading and trailing edge of a blade. If the blade has a shroud platform, its profile should be also measured (and possibly the gland packing profile). It is also necessary to measure the feather end and base of blade profile. Finally, a separate independent task is the blade tang profile measurement.

Evaluation of bolted connection with gland packing and live-load device

Evaluation of bolted connection with gland packing and live-load device

Turbine Blades Profile and Surface Roughness Measurement

The article presents the study of a turbine blade profile and roughness measurement processes - the task every manufacturer of this part needs to resolve. The blade is one of the most complex parts to manufacture because of its complex profile. This profile should be measured in several sections on the feather of all profile elements - the suction side, pressure surface, leading and trailing edges of a blade. If the blade has a shroud platform, its profile should be also measured (and possibly, the gland packing profile as well). It is also necessary to measure the feather end and the blade profile base. Finally, a separate independent task is the blade tang profile measurement.Surface roughness should be also measured on all the blade surfaces.

Double mechanical seals can benefit environment

The mining industry presents a number of challenges for engineers, linked to scarcity of water and high-pressure transfer slurry pump applications. This article looks at two case studies that show how upgrading from gland packing to double mechanical seals has improved performance and made dramatic water savings.

A Case Study on Application of DMAIC to Improve Delivery Efficiency

In this era of globalization, as competition intensifies, providing on timely delivered products and services has become a competitive advantage and a need to ensure survival. The Six Sigma’s problem solving methodology DMAIC has been one of the several techniques used by organizations to improve the deliveries of their products and services. This paper is based on an application of Six Sigma and DMAIC to improve on time deliveries within a MDF boards manufacturing organization in Sri Lanka. The paper follows the DMAIC methodology to systematically investigate the root causes of delivery failures and provide a solution to improve them. It begins with the past data analysis of the problem to find out major causes for delivery failures and after finding major causes further analysis is done to find out sub critical causes. Then reasons are analyzed for these sub causes and for these analyses Pareto charts, Brainstorming, Fish bone diagrams and verification sheets are used as tools and techniques. Finally to find out key root causes 5Y analysis is used and solutions have been proposed to overcome these issues. Product quality issues and Plant availability issues were the most problematic cause for delivery failures. Further analysis noted, Shives, Crack marks and Rough surface were the most problematic quality defects and to loss plant availability several mechanical and production related plant down time issues were caused. Metering belt broken, Doffing rolls drive chain broken and fibers leaking from gland packing at refiner 01 were the most significant causes identified as mechanical related plant down times and out feed board blockage, refiner 01 blow line blockage and forming line scalper exhaust line blockage were the most significant production related plant down time causes. This paper can be used as a guiding reference for managers and engineers to undertake specific product and process improvement projects, in their organizations, similar to the one presented in this paper. This study presents an industrial case which demonstrates how the application of Six Sigma and DMAIC can help manufacturing organizations to achieve product quality and plant availability improvements in their companies and thus contribute to their search for improvement of on time deliveries.

Failure Investigation of a Gate Valve Eye Bolt Fracture During Hydrotesting

During preparation for a hydrotest on a 6-in. liquid discharge line of an onshore gas terminal, water was observed to be dripping from the gland packing on the isolation gate valve. On closer inspection, it was found that the gland eyebolt on the valve was fractured. The fractured sample was sent for metallurgical examination to determine the cause of the fracture. Results of this investigation suggest that the brittle fracture of the eyebolt was caused by hydrogen embrittlement (HE). The eyebolt was supplied with the wrong composition and hardness, thereby producing increased sensitivity to HE. This article illustrates the typical procedure for a metallurgical failure investigation and presents the results of the investigation, lessons to be learnt and remedies to be applied to prevent re-occurrence. The main recommendations are to; review the valve supplier’s quality assurance procedures and to ensure that new valves are supplied in the specified composition and hardness; carry out positive material identification tests on all existing stock of Class 600 gate valves and consider using tempered plated bolting for the high risk (hydrogen-rich environment) environment.

Shut-off device for well-head equipment

Today, a large number of direct-flow gate valves with a single slide plate are used in the petroleum industry, and, in particular, for oil and gas recovery. Moreover, the service life of well-head equipment in Russia may attain many tens of years. In this respect, modernization of these gate valves for the purpose of extending their service life and lengthen their inter-repair period is urgent. The tendency currently exists to broaden use of gate valves with a stationary spindle; however, the assigned running time to loss of serviceability of the sliding couple is not always realized. The following modernized gate valve has been designed: with an extensible spindle, and with no opposing rod; and, a special mechanical drive is developed. The gate valve developed permits a significant increase in running time to failure of the gate and packing gland; an appreciable reduction in the control force; and, retention of ease of use at the series-production level. Modernization of the gate valve makes it possible to extend the inter-repair interval and running time to failure, and reduce the control force.

Determination of lateral pressure coefficient of gland packings taking account of radial loads

Equations are given for determining radial loads on outer and inner gland packing contours (surfaces) that allow estimation of the lateral pressure coefficient of the packing.

Application of shape memory materials in fluid sealing technology

PurposeThe purpose of this paper is to present short characteristics of shape memory alloys (SMA) and shape memory polymers (SMP) and some examples of application of these materials in industrial sealing technology.Design/methodology/approachIn this paper, short characteristic of shape memory materials and design examples of applying them in industrial sealing technology such as: tube coupling in hydraulic systems, flanged pipe connections, lip radial seal, mechanical face seal, soft gland packing, magnetic fluid seal, and in bearing seal system for drill bit, are given.FindingsThe paper provides information about innovative fluid seal designs based on particular properties of the shape memory materials, applied in stationary joints, and rotary equipments. These new solutions provide often to simplify seal design, their miniaturization, increase of tightness, and reduction of operating costs.Originality/valueThis paper offers some new fluid seal designs based on the shape memory materials and their practical application in industrial sealing technology.

Determining the internal friction coefficient for gland packing

A method is proposed for determining the internal-friction coefficient fi.f of gland packing based on thermally expanded graphite (TEG). The fi.f calculations are based on experimental data for packing of three types: N1100, N1201, and N5001.

Permeability of gland packings made from heat-expanded graphite

Several types of square-shaped gland packing interlaced from graphite fibers (reinforced with cotton thread or fiberglass fabric impregnated with fluoroplastic suspension) and from aramide fibers impregnated with fluoroplastic suspension have been investigated. Equations correlating permeability coefficient and unit load have been derived.