API RP 1133:2005(2010) pdf download

API RP 1133:2005(2010) pdf download.Guidelines for Onshore Hydrocarbon Pipelines Affecting High Consequence Floodplains.
4.3 MATERIAL SPECIFICATiONS FOR TRENCHED AND DRILLED CROSSINGS
Materials specified tar a pipeline crossing should comply with previously established practices and standards for pipeline construction. Allowances shoukl be made for any additional stresses that may be induced during the inslaibtian of the pipeline, particularly in the case of a directionally-drilled cmssrng. More information on pipeline design can be found in ASMI B31.4 and ASME B31.. Analysis of stresses induced during the installation of a pipeline crossing should be performed by a qualihed professional engineer.
Pipe specifications should include limitations on maximum, as well as minimum, yield strength. The selected grade of pipe should provide sullicient ductility to minimize the likelihood of damage during installation. Additional wall thickness or pipe yield strength should be considered as a corrosion allowance in areas where nlirigation or repair would be dithcult or impossible (i.e.. a drilled crossing I.
Buoyancy calculations must he made for trenched crossings to ensure that the pipeline will not fksat after installation, The pipeline LT(w.smg should be designed with an adequate safety factor to provide negative buoyancy during all anticipated conditions. The pipeline will float if the weight of die pipe and coatig i less than the fluid dispbxd by the pipeline. The greater density of salt water mtrt be accounted for when cnwsbig call-water courses. Binoincy can he contmlled by the use of continuous concrete coating, concrete weights or serew anchoes. T’picaI buoyancy calcuiations may be found in Pipe line Rule.c of Thumb Harnlborst or AGA Sub,narine Piprline
ftg Siubiiiri’ Anul’i.cis and 1ksisn Gwdelisrrer.
In addition to providing protection against corrosion, pipe and weld joint-coating systems for trenched and directionally-drilled crossings should be sutliciently durable to prevern damage during installation. II gravel or nick is expected to be encountered. the coating system should include a highly abrasion-resistant, snwioth.surfaced outer layer with a high hardness factor. The outer coating should be well bonded to the first layer coaling. 1kw example. the first layer of coating could he a lu.sinn-bonded epoxy FBF.l of 22 mils — 24 mils and the outer coating could he an epozy-ba.scd polymer concrete of 40 mliv —60 mliv,
4.4 VALVES
4.4.1 General
Block or check valves should bc corniidcrcd on pipelines crossing floodplain’. adjacent to large watercourses to limit the volunie of a potential release. The check valve acts as a one-way (low device and automatically prcvcnts the backwant flow fmm the downstream pipeline section into lower elevations within the (loodplain The block valve can be operated either locally, automatically or remotely to isolate the pipeline in the floodplain from upstream and downvtrcam pipeline scction%
A sancty ot salve types can he used and their efkctivenesv depends on proper design, location, and prompt action hy the pipeline operator or control system 10 nunimitc a pipeline release.
44.2 Determination of Valve Type and Location
The type. location and necessity of block and/or check s-alses should be based on an engineering/risk ana yvis of the floodplain and should take into account the following variables:
a. Uses of the watercourse tharge trallic. potable waler supply. farm irrigation, etc.).
h. Environmental concerns.
c. Tupugraphic condition’. Ipotenhial spill volume).
d. Matenal’. being transported.
c. Access.
f. Avubbiliiy of power and continunication (if stlses are or will he automatically or remotely operated in the future).
g. Sectirity.
h Regulatory requirements.
The pipeline’s elevation profile is one important factor to be considered when choosing salve locations.
It is important that valves be installed at locations accessi• Nc during flood conditions. If salves must be installed within a floodplain. barricades, salve guards, or other mcans of protecting the salve from floating debris during flood conditions should be considered.
The type of salve actuation method selected by the designer should he coonlinated with the requirements imposed for closure, materials being transported. compatihilfly with technology currently used, availability of energy sources. asailabilits of renwite conlmunications. and maintenance requiremenLs. A variety of valve actuation methods may be employed depending on the application and can include the following:
• Manual.
• Hydraulic.