API 574 chap 4-5 Flashcards
The two most common carbon steel piping materials used in the petrochemical industry are
ASTM A53/A53M and ASTM A106
Piping of a nominal size larger _______ is usually made by rolling plates to size and welding the seams
than 16 in. (406 mm)
Steel and alloy piping are manufactured to standard dimensions in nominal pipe sizes (NPSs) up to?
up to 48 in.
Centrifugally cast piping can be cast then machined to _______ thickness.
any desired
Pipe wall thicknesses are designated as pipe schedules in NPSs up 2?
up to 36 in.
The size denotes the actual OD for NPSs equal to or greater
than 14 in. (356 mm).
Allowable tolerances in pipe diameter differ
from one piping material to another
The actual thickness of seamless piping can vary from its nominal thickness by a manufacturing tolerance of as much
as 12.5 %
The under tolerance for welded piping is
(-) 0.01 in. (0.25 mm).
Cast piping has a thickness tolerance of +/-
+1/16 in. (1.6 mm) and –0 in. (0 mm),
Cast iron piping is generally used ___and not recommend for__-?
for nonhazardous service, such as water; / for pressurized hydrocarbon service because of its brittle nature.
FRP design/testing code ? (2)
- ASME B31.3, Chapter VII covers design requirements for nonmetallic piping.
- American Water Works Association (AWWA) is an organization that also provides guidance on FRP pipe design and testing.
limitation of FRP codes?
do not offer guidance as to the right choice of corrosion barriers, resins, fabricating methods, and joint systems for a particular application.
What is recommended for user to do if looking to use FRP?
consider other sources such as resin and pipe manufacturers for guidance on their particular application.
many of the failures in FRP piping _____ practices
are related to poor construction practice
FRP pipe can experience _______over time if not adequately protected.
ultraviolet (UV) degradation
What table can be used as a guide to identify liner and structure imperfections that are common in FRP laminates. ?
ASME RTP-1, Table 6-1
FRP piping systems commonly called “commodity piping” are manufactured for a variety of services and are sold as products with a predetermined
design, resin, corrosion barrier, and structure.
Nipples are normally what length
6 in. (152 mm) or less in length
Secondary piping is normally isolated ? and examples?
from the main process lines by closed valves and can be used for such functions as sample taps.
Auxiliary piping is normally open ? and examples
to service but can be isolated from the primary process.
Examples include flush lines, instrument piping, analyzer piping, lubrication, and seal oil piping for rotating equipment.
Tubing stated size is the ____except for steam tracing and that size is _______less___?
actual OD rather than NPS. /s ize designation is 1/8 in. (3.2 mm) less than the actual OD.
A commonly used tubing material is the
18Cr-8Ni family of stainless steels, such as Types 304 and 316.
Types 304 and 316 they are susceptible to
pitting and chloride stress corrosion cracking (CSCC)
gates valves is not generally designed for
regulating fluid flow
what does gate valve called a full-ported valve mean?
have port openings that are approximately the same size as the valve end openings
another name for gates valves? (full port only)
block valves
Reduced port gate valves have port openings that
are smaller than the end openings
globe valve, which is commonly used to
regulate fluid flow,
globe valve body contains _____ move ____ disc axis and contacts ____
circular disc that moves parallel to the disc axis and contacts the seat
For globe valve The seating surface can be (2)
flat or tapered.
For globe valve and for fine-throttling service, a very _____seat can be used; this particular type of globe valve is referred to as a _____
steep tapered / needle valve.
plug valves (4)
- function as block vale to close off flow
- valve is closed by turning the plug 1/4, right angles to the opening in the valve body.
- operated via gear or turning a wrench
- lubricated or non lubricated
ball valve (4)
- 1/4” turns
- spherical not tapered or cylindrical like plugs
- suited for quick on/off or bubble tight services
- equipment with elastomeric seating material that provide good shut off.
diaphragm valves (2)
- used for corrosive service below 250F, where leak tight valve is needed
- function as a closure and a seal
butterfly valves (4)
- 1/4” turn
- often used for low pressure service for coarse flow control
- large BV are mechanically operated
- tight shut off in low / high pressure services
slide valves (5)
- used in erosive or high temp service
- flat plate that slides against a seat
- does not make a tight shut off
- typically used to control fluidized catalyst flow
- expose to high wear from the catalyst
types of fittings (2)
- metallic
2. frp
ASME B16.5 covers flanges of various materials
through a NPS of 24 in.
ASME B16.47 covers steel flanges that range from
NPS 26 through NPS 60.
type of expansion joints (2)
1 . metallic bellows - high-temperature services
2. fabric joint - flue gas services at low pressure and where temperatures do not exceed the rating of the fabric material.
flexible houses purpose(2)
- transfer hydrocarbons and other process fluids on a temporary basis to facilitate turnaround activities
- mitigate the effects of thermal expansion, vibration, or movement during normal operations
what require special connections/joining methods due to inherent design characteristics (2)
cast iron piping and thin wall tubing
Threaded joints are generally limited to (2)
- auxiliary piping in noncritical service
2. that has a nominal size of 2 in. (51 mm) or smaller.
why A large number of piping failures occur at pipe-to-pipe welded branch connections?
- branch connections are often subject to higher-than-normal stresses caused by excessive structural loadings from unsupported valves or piping, vibration, thermal expansion, or other configurations. ( tri-axial stresses )
how to minimize failures at welding branch connections? (2)
- Use of Weld-o-lets
2. forged piping tee
Some common joint designs in FRP pipe systems include (4)
- bell and spigot,
- butt and wrap,
- taper-taper, and
- flange-flange
Bell and Spigot/Taper-taper need proper…(3)
- Proper surface preparation, insertion, and adequate adhesive are the key to make these types of joints
Butt and Wrap
butting plain end pipe together and applying layers of resin and fiber reinforcement layers around the joint.
Flange joints require proper (2)
gaskets and torques.
Tubing size is actually
OD size not NPS
socket weld are generally used for what size ?
2” and smaller
OSHA 1910.119 mandates that?
piping be isnpected to a code or standard such as aPI570
plug and ball valves function as
block valve
what is not normally used in in inspection for CUI
VI
