MECH1200 SEALS, GASKETS & SEALANTS

MECH1200 WHAT CAUSES LEAKS Causes of leakage –Worn or damaged seals –Worn or damaged gaskets –Worn or bent parts or shafts –Fasteners over tighten or too loose –Wrong parts or gaskets –Nicks or burrs –Improper installation

MECH1200 SEALS Purpose: Keep the oil in and the dirt out Separate fluids or cavities Withstand different pressures

MECH1200 SEALS Originally made from old felt & leather seal. Most seals are made of Nitrile. Special Seals are made of Viton, Silicone, Polyacrylics or chemical resistant materials.

MECH1200 SEALS Seals can be: 1. Spring-loaded 2. Spring-less 3. Single-lip 4. Multi-lip

MECH1200 SEALS

MECH1200 SEALS A. The flexible material component of the seal produces the lip. In this design there is only one lip, the primary sealing lip B. The outer shell of the seal holds the seal in place. C. The garter spring (found in most seal designs) is a coiled wire spring that provides a controlled radial load over time.

MECH1200 Inspect the shaft that the seal rides on; it might be bent or damaged. SEAL INSTALLATION

MECH1200 SEAL INSTALLATION 1.Install with lip (and garter spring) toward liquid. 2.Lubricate lip before installation. 3.Use sealant on the outside of steel seals. 4.Use a seal installer.

MECH1200 GASKET A pliable material that is shaped and placed between two mating machined parts to form a seal. Purpose of a Gasket –To confine; gas, oil, water, vacuum or exhaust –Seal out foreign objects such as dirt & water –Must withstand heat, cold, pressure, erosion, corrosion, moisture and oil

MECH1200 GASKET MATERIALS Gasket Materials –synthetic rubber –cork-rubber –embossed steel (Corrugated) –paper

MECH1200 GASKET MATERIALS cork-rubber synthetic rubber

MECH1200 embossed steel (Corrugated) paper GASKET MATERIALS

MECH1200 GASKET INSTALLATION 1.Use a quality gasket 2.Use alcohol or brake cleaner on a clean rag to wipe the oil off of the machined surface 3.The surface must be dry 4.Apply a gasket sealing liquid if recommended 5.Tighten in steps 6.Use the proper torque pattern when tightening 7.Torque to proper specs

MECH1200 Stuffing Box An assembly which is used to house a gland seal. It is used to prevent leakage of fluid, such as water or steam, between sliding or turning parts of machine elements.

MECH1200 Stuffing Box GASKET MATERIAL Normally a graphite impregnated woven rope

MECH1200 Stuffing Box

MECH1200 Stuffing Box

MECH1200 Stuffing Box

MECH1200 O-Rings O-rings come in several sizes the most common standard sizes are 1/16, 3/32, 1/8, 3/16, 1/4

MECH1200 O-Rings come in several shapes –O being the most common – D shape, –Square-ring – Modified X Challenger disaster O-Rings

MECH1200 O-Rings also come in different types of material to ensure compatibility with the fluid being contained O-Rings

MECH1200

USING SEALANTS Use proper sealant for application. Do not use a sealant unless specified in service manual or by gasket manufacturer. Types of sealants –Hard drying like 3M Weather-stripping or a glue to keep a gasket in place –Aerobic (RTV) cures when exposed to air –Anaerobic cure after the components are put together (Thread lockers)

MECH1200 Aerobic (RTV) RTV - Room Temperature Vulcanizing –Called Silicone Sealant –Replaces most gaskets –Forms a rubber seal by absorbing moisture in the air –Sets in about ten minutes. Dries in about 2 hours fully cures in 24 hours. –Cure times will vary with Temperature, Humidity, and size of the gap

MECH1200 Aerobic (RTV) –Blue is the most common color but also comes in Black, gray, bronze,clear, red and white(white is for the bathroom)

MECH1200 Blue Thread lockers Medium Strength for all bolts ¼ or larger Able to Remove with hand tools Prevents parts from loosening from vibration Protects threads from corrosion Recommend for valve cover bolts, rocker arm nuts, carburetor studs, motorcycle, jet skis snowmobiles etc. Applied BEFORE Assembly

MECH1200 Red Thread lockers High strength requires heat to remove Works well for studs and press fit Locks against heavy vibration Requires extra effort to remove or special tools like heat. Without heat part may shear before thread locker releases Applied BEFORE Assembly