What is Seal: Definition and 48 Discussions

The United States Navy Sea, Air, and Land (SEAL) Teams, commonly known as Navy SEALs, are the U.S. Navy's primary special operations force and a component of the Naval Special Warfare Command. Among the SEALs' main functions are conducting small-unit special operation missions in maritime, jungle, urban, arctic, mountainous, and desert environments. SEALs are typically ordered to capture or to eliminate high level targets, or to gather intelligence behind enemy lines.All active SEALs are male and members of the U.S. Navy. The CIA's highly secretive and elite Special Operations Group (SOG) recruits operators from SEAL Teams, with joint operations going back to the MACV-SOG during the Vietnam War. This cooperation still exists today, as evidenced by military operations in Iraq and Afghanistan.

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  1. L

    Difference between Boss seal industrial vs military fittings SAE specs

    Hi - attached is 3 pages from the PARKER o ring guide and I am having trouble with specs in the military straight thread tube fitting chart not fitting the designated o-ring. I can't find a different resource for something in my thread size needed - 5/8-18 Does anyone have an alternative...
  2. C

    Need a surface mount seal for chemical cabinet door

    I want to build a mini chemical cabinet to try to eliminate odors in my garage as my wife thinks the car interior now smells. The chemical resistant rubber strip sealant is crazy expensive, but as the intended use will just be fumes with no actual chemical or fuel contact to the seals, can I use...
  3. H

    Looking for a grease/lubricant that is resistant to chloroform

    I'm doing an experiment in a system that I use chloroform, and the apparatus needs to be sealed by a grease so that chloroform won't leak out. I've been using fluorine-based grease/lubricant to seal since conventional silicone-based grease/lubricant will easily be dissolved by chloroform, but...
  4. A

    Mercury Seal Gap Size: Is it Possible?

    I am wondering about the physical properties of mercury. I know that different materials have different density and ability to penetrate small openings. I wonder if I have a small container of mercury, say about 100 grams or less, and there is a small flat opening at the bottom of such container...
  5. Roy S Ramirez

    How many O-rings would a mechanical engineer use here?

    Hello everybody! Happy 2019! I'm trying to design a mechanical face seal for the part shown below, and I'm struggling with the number of o-rings I'm supposed to use. There are two cavities (rings) for two different fluids. The liquid dynamic pressure for both the internal and external fluids is...
  6. T

    Seal rotating parts/reduce friction (hand-tight thread)

    I am working on a design where I have a block which has a cap assembly fitted to it - see images attached. The cap assembly is constructed of: - Main body with two holes through (flowing water in and out) - Locking ring with a threaded outside, grooves for tightening by hand and two o-rings...
  7. S

    Calculating Friction Force for a Waterproof Seal in a Syringe Setup

    Hi Friends, So I'll go into a bit of the setup that I'm having some trouble figuring out. I have a piece of rubber that will be pushing up against the side of a metal (or plastic) container to create a waterproof seal. The easiest way to think about this would be to imagine the rubber piece of...
  8. S

    Seal friction needed for pneumatic/hydraulic piston

    Hello, I have a project that requires me to calculate break force friction of a piston seal on the cylinder wall. I have a double acting cylinder at very low pressure, 3.5" diameter bore, one side of the piston is air, the other side is water. What seal type, seal compression, lubrication and...
  9. Parsifal1

    Sealing Solutions for Rotating Overlapping Cylinders in Water Applications

    I'm trying to make two metal cylinders which will overlap to act as a valve for the outer cylinder to rotate around the other. I need to be able to stop water from the reservoir around the outer cylinder from leaking down between the plates and into the gap for the gear which will give the...
  10. Ravi Singh choudhary

    What pressure not increases if I seal the container?

    CASE1: A container with some water is open to atmosphere, pressure is definitely atmospheric, no somehow I put cover over it and sealed it also. Pressure would increase because new equilibrium will establish between water and its vapour so pressure will increase in the closed container. CASE2...
  11. Scott Q

    Looking for flexible seal for oscillating thin opening

    Hello Everyone, I'm looking for a sealing membrane, or comparable solution, to seal a thin opening (~15mm x 2mm) that oscillates elliptically, like in my example picture below, with a low amplitude (+/- 1mm) and frequency in the 100s - 1000s of Hz range. Any ideas?
  12. R

    How to calculate the strength on adhesive seal using ansys?

    hi all, I am rajesh,now I am working with adhesive sealants,here,adhesive failure modes are adhesion and cohesion. In Ansys workbench how to validate the these two failures.so please give me a needful information.
  13. M

    Will Decreasing Stem Diameter Affect Seal Point?

    Hi All, Me and my friend are having a dispute on whether or not, decreasing the diameter of the stem from 30 to 15mm will have any impact on the sealing point as shown on the picture attached. Can you please help if you can?
  14. M

    Does mylar provide a secure seal?

    I'm using mylar pouches to seal phase change cooling liquid to experiment with cooling in athletic apparel. This is an example of the type of 'phase change' liquid I am trying to seal...
  15. B

    What are the best options for high purity reciprocating seals at 3000psig?

    I have an application which requires a high purity reciprocating seal at 3000psig. An AS 568 size -002 o-ring is the size I need or close to it (must work on an nominal ∅.046" shaft.) Teflon or FFKM (like Kalrez etc.) would be acceptable, but spring energized Teflon seals are tougher at that...
  16. B

    What materials are best for a high pressure face seal?

    Hi, I'm doing a design which requires a face seal with internal gas pressure of 3000 psig. An elastomer face seal at that pressure may run into some issues. The threaded connection between the parts that retain the seal is small and the female thread is alum which will strip under high...
  17. V

    The right method to put an oil seal in a housing

    i have a question, when i put a oil seal in a housing, should i put grease between the housing and the oil seal? because that is more easy to out in. Can explain the theory to me please?
  18. G

    Calculating the weight of an object required to overcome grease seal

    Hi I am trying to work out a problem with a piece of equipment: imagine a container that has grease injected into it at say 3,000 Psi The container has a piece of wire running though the middle vertically with a 100lbs weight attached to bottom. Only the wire is in contact with the...
  19. C

    Can Cast Iron Pistons Seal Without Seals?

    as far as i understand, piston have cast iron seals because of the properties of cast iron, which make it a sealing material. but i was wondering, if the cylinder and piston are both made of cast iron and closely fitted together, could we avoid using seals all together? friction doesn't depend...
  20. S

    Gland and Seal for Brake Hydraulics Question

    Greetings, I'd like to solicit assistance relative to a brake hydraulic system. I am rebuilding a vintage system that contains a pressure differential unit. The unit contains a dynamic piston with seals in a fixed bore. The seals are intended to keep fluid outboard of them in the bore. I...
  21. T

    Liquid Flow through a ruptured seal

    I am researching flow through blister packs and trying to derive an equation that can relate flow rate to a plunger position. If I cannot describe the problem well, I will upload a picture that can give a better idea. I have an igloo shaped blister pack made of aluminum foil. A plunger moves...
  22. 0

    How do you make a 1 kilometer seal?

    There is a German professor for whom the polls are still open on which side of the genius/lunatic line he is. Since the main problem with renewable energy is saving it for the time, when there is no sun or wind, he wants to build a giant energy storage. Available water reservoirs are scarce so...
  23. P

    Find the max height of the second projectile relative to seal level

    Homework Statement A projectile is launched at 110.0 m/s at 40.0° above the horizontal off a cliff that is 250.0 m above sea level. After 4.00 s of flight, this projectile launches a second projectile at 50.0 m/s directed at 15.0° below the horizontal. a) Find the max height of the second...
  24. F

    Labyrinth Seal Leakage Calculation ?

    I'm studying mechanical engineering, just have a question on the labyrinth seal leakage equation. More specifically, the expansion ratio formula. What does the '1n' stand for? With 'n + 1n', I'm assuming those two n's are different since one looks like it's in italics and the other...
  25. D

    Making a vacuum seal with a screw?

    I apologize for my lack of mechanical term knowledge. I'm looking for a type of screw I could use in a project. Sorry if the thing is unrealistic or if the part is obvious. I attached a sketch of what I'm looking for. The screw would never be completely out of the hole like the sketch...
  26. G

    Rotary Seal Ideas for PVC Pressure Housings Underwater

    Hey guys, So I need some ideas on how to best make some rotary seals (or a good alternative) for a school project I'm working on (which has a very tight budget). I'm creating some small PVC pressure vessels to put some medium sized RC servos in, and I need to run the servo's drive shaft (or...
  27. A

    Polar bear family's noise seal feast

    This unique 6-minute video shows a she-bear and her two cubs devouring a seal, while mummy bear is growling for miles around to be heard, to warn off others from getting too close. http://www.dagbladet.no/2011/09/07/nyheter/innenriks/isbjorn/dyrenes_nyheter/17989869/
  28. T

    Seal Team Six Helicopter Crash 5/1

    As I guess everyone knows, during the Bin Laden raid the Seal's stealth helicopter crashed. Several things were offered as possible reasons: the stealth modifications altered the flight characteristics in unpredictable ways, it was more humid or hot than they expected, and that the high walls...
  29. P

    Understanding Hermetic Seals on Centrifuges: Types and Conversion Possibilities

    Hi all, I am currently in the process of identifying a continuous lab scale liquid-liquid centrifuge for developmental work that may translate to our production unit. We know that only hermetically sealed unit would work for our type of separation, but the issue I encounter is that I either...
  30. G

    High temperature pressure vessel seal

    Hello, I am looking for a seal design that would seal between the end plate and cylindrical section of a pressure vessel . The vessel is made of hastelloy X and has a working pressure of 4000 psi and a working temperature of 1600 deg F. ------------- ------ ...
  31. Y

    High Temperature Flexible Seal

    I am working on a project where I need a high temperature sealing element. You can see the system in the attachment. My moving object is moving linearly in a motion slot which is constructed on a sheet metal plate. But the surrounding temperature in this process is 500 C degree and there...
  32. Y

    High temperature flexible seal

    I am working on a project where I need a high temperature sealing element. You can see the system in the attachment. My moving object is moving linearly in a motion slot which is constructed on a sheet metal plate. But the surrounding temperature in this process is 500 C degree and there...
  33. G

    Materials for dynamic seal application

    I am about to talk to a prototype company and need some advice on O ring, friction and seals. I am creating a device that works on slight water pressure differential. I have a piston like structure that is cylindrical and there will be an o ring inside the cylinder. The gas/liquid that the o...
  34. E

    What exactly is a seal pump and how does it work?

    I've come across seal pumps in a few power plant diagrams recently and I'm confused on what a seal pump actually does. As it was explained to me, the seal pump pumps water into/around a primary pump to seal the primary pump from leaks. However, something seems to be missing from this...
  35. M

    Mechanical seal monitoring system ?

    mechanical seal monitoring system ? hello everyone i have a system consists of A blower used for nitrogen cooling this blower has a mechanical seal which is cartidge seal and the seal cooling liquid is water pumped from a water tank via a water pump to keep both surfuces of the seal...
  36. M

    Designing a Mechanical Seal - A Step-by-Step Guide

    can i design a mechanical seal ?
  37. S

    Linear Dynamic Seal (water-tight)

    I'm trying to conceptualize a design for a hydro generator that basically operates by moving an airfoil up an down along a straight path. Most of it is all worked out, except for the issue of water sealing. If you can make sense of my not-so-great drawings, the airfoil is attached to the...
  38. J

    News What would probably be the most impactful steps to stop seal bashing?

    Ideas? So far, I have thought of making a club at my school to create awareness and to encourage people to take some kind of action to stop it?
  39. S

    Some question about floating seal

    Some question about floating seal Hi, everyone, I am designing a pulley that can be placed in 10-25m slurry (or you can treat it as sea water I think). Some ppl suggest that using a floating seal is much better than lip seal with back bone in such relatively high pressure situation. Due to the...
  40. H

    How do you seal a rotor underwater?

    Lets say I will be operating a generator underwater in a "box" sitting on the river floor. Turbine blades will be spinning a rotor attached to said generator, and obviously the turbine blades are exposed to the water and the generator is sealed in the box. I'm having trouble identifying what...
  41. M

    Shallow Water Seal Design for ROV Thruster Assembly

    I asked another question in a previous thread, but this is a new issue so here's a new thread: Basically I need to design some kind of waterproof shaft seal for the use of an underwater ROV. Following some earlier advice, I looked into the Parker O-ring Handbook and found the easiest way is...
  42. M

    HELP NEEDED with CHOOSING THE RIGHT SEAL for a rotating furnace

    I am a mechanical engineering student and have a desin project application question. In the picture, as you can see, the working tube, is a glass cylindrical tube, mounted onto main body of the furnace using a motor that rotates the tube at certain RPM. This is an open ended tube, and the blue...
  43. L

    Do Harp Seal populations effect Atlantic cod?

    [SOLVED] Do Harp Seal populations effect Atlantic cod? The Atlantic cod population was an extremely abundant stock of primary economic importance to fishing communities throughout the Atlantic provinces. The Department of Fisheries and Oceans has stated that the collapse in Atlantic cod stocks...
  44. T

    Can You Calculate Seal Temperature Using Known Variables?

    Is there an formula to calculate temperature on a seal if rpm, pressure, time and coefficient of friction are known? Thank you. Sincerely The TallOne
  45. K

    What Alternatives Exist to Mercury Seals for High RPM Generators?

    Hi, While designing a high RPM generator i need some information on mercury seal. Actually i want to establish contact between rotor(25k to 30k RPM) and stator. Anybody can suggest me any other alternatives.
  46. A

    Elastic Hot Gas Seal - Up to 1200°F & 1 Atm Pressure

    Hello people :smile: Again I need some help...:shy: I'm looking for a type of cloth that can be used to seal a gas at up to 700 degrees C (about 1200 F) and a pressure difference of up to 1 atmosphere. Just to explain a bit more, I want to seal gas between two sections of a jet engine...
  47. Q

    Calculating differential pressure across a seal

    Hey I need help trying to calculate the differntial pressure across a seal. I know the tensile strength of the material used for sealing and the difference in the 2 diameters of the 2 cylinders that need sealing. Only problem is the distance is 0.3m and my seal is 3m long (the whole thing can...
  48. B

    Mechanical seal for ROV thruster

    I am designing an ROV thruster to be used in either salt or fresh water at depths to 100 meters. I am trying to find an appropriate mechanical seal to seal the propeller shaft. This is for my own personal use so I'd like to keep the costs somewhat reasonable. I have been trying to find a...