Marine Survey Practice

(1)

Marine Survey

Practice

This blog intended to provide information and experience to professionals who work in

the difficult career of Marine Surveyor.

Wednesday, January 30, 2013

Surveyor Guide Notes for Boiler Survey

Boiler Surveys (Including Thermal Oil Heaters) General

A complete boiler survey allows us to check out if any build-up of deposits has taken place, and

deformations or wastage of plate work, piping or any of the various parts, which may compromise the sale working order of the unit. The survey should include research as to cause of any anomalies found and also their correction.

Any repair will have to ensure the sale working order of the boiler until the next survey.

A complete survey means a lull internal and external examination of all parts of the boiler and accessories such as super heater, economizer, air-heater internal organs and all mountings. This examination may lead the Surveyor to require thickness gauging of plate or tubes that appear to be wasted and eventually to a lower assigned working pressure, if calculations prove this necessary.

(2)

Collision chocks, rolling stays and boiler stools are to be examined. The oil fuel burning system is to be examined under working conditions and safely devices are to be checked, including any automatic burner light-up sequence to verify purging of the furnace prior to lighting burners. A general examination is to be made of fuel tank valves, pipes etc. and fuel pipes between pumps and burners.

Safety valves are to be adjusted to a pressure not greater than 105 % of design pressure.

Water-tube boilers

Typical survey plan

The main points to remember are:



At superheat temperatures > 400 °C special steels and more advanced welding techniques

(3)



Check drawings of unfamiliar designs of boiler to correctly plan the survey.

Steam drum and tubes

Pitting, fit of manhole door

Super heater

Short-circuiting, erosion in headers. Weld fractures.

Boiler casing

Overheating, leakage.

Furnace

Distortion of tubes, bulging of tubes. Condition of

baffles Refractory.

Water drums

Pitting fit of manhole door.

Scotch boiler type

Typical survey plan

The main points to remember are:

(4)

Furnaces

Overheating and subsequent distortion

Combustion Chambers

Overheating and distortion of crown.

Leaking tubes and stays.

Tubes

Thinning at ends, repeated expansion.

Shell Internal

Wastage, grooving

Shell External

Wastage, in way of leaking mountings.

Cochran type boiler

The main points lo remember for these varied designs are similar to the foregoing:  Wastage, lire and water side.

 Deformations due to overheating.



Leaking lubes.

 Wastage externally due lo leaking mountings, manholes and handholds.

Hydraulic testing

Following major repairs or as required by the Surveyor hydraulic testing may be required.

(5)

P = Working pressure in bars.

Before 1.25 P if P < 40 12th year 1.2 P + 2 if P > 40 After 1.15 P whatever P 12th year value

Typical safety valve designs

Pressure tightness tests at working pressure may also be carried out after small maintenance jobs such as part re-tubing, renewal of rivets or extensive caulking of seams or rivets, welding of small cracked areas.

Plugging of Boiler Tubes Water tube boilers

Screen tubes - These are the first rows of tubes and are exposed directly to the flame, they are gene rally very closely slacked lo afford protection to the super-heater elements which lie behind.

Wale wall tubes - these are subject to the same defects as screen tubes, but more sensitive to poor circulation, particularly roof tubes.

(6)

Any tubes found plugged or (bulged) should be renewed.

Main steam generating lube bank - a maximum of 10 % of the tubes may be accepted plugged before renewals are required.

Note: In all cases of boiler problems it is important to ascertain the cause of damage (flame impingement, lack of boiler water treatment etc.) and take remedial action.

Smoke tube boilers

Any tubes found plugged should be renewed.

Tubes with excessive thinning at the ends because of repeated rolling or showing signs of movement should be renewed.

(7)

(8)

Posted by Harry González at 17:24

Email ThisBlogThis!Share to TwitterShare to FacebookShare to Pinterest

Newer PostOlder PostHome

Total Pageviews

54,318

About Me

Harry González

View my complete profile

Translate Powered by Translate Entries  ▼ 2013 (50) o ▼ January (50)  Code of Ethics.

 The Underwriter's Surveyor  Salvage Surveys

 Guidelines on survey for Marine Surveyor.  Preparation for Survey

 Hull Survey Methods  Failure and Damage

 Notes Relative to Shell and Deck Plate Repairs  What to look for?

 Surveyor Guide Notes for Weld Inspection and Repai...  Repair Quality Standard for Existing Ships

 Surveyor Guide Notes for Coating Condition Survey  Initial Survey of Hull

(9)

 Annual Survey of Hull

 Surveyor Guide Notes for Outside Inspection of the...  Surveyor Guide Notes for Anchors and Chains Survey...  Surveyor Guide Notes for Bilge Keels Survey

 Surveyor Guide Notes for Doors Survey

 Surveyor Guide Notes for Rudder, Rudder Stock and ...  Surveyor Guide Notes for Propeller Surveys

 Intermediate and Periodical Survey  Renewal Survey

 Surveyor Guide Notes for Additional Surveys  Surveyor Guide Notes for Reporting

 Surveyor Guide Notes for General Cargo Ships Surve...  Surveyor Guide Notes for Hatch Covers of Dry Cargo...  Surveyor Guide Notes for Bulk Carriers Survey  Surveyor Guide Notes for Oil Tankers Survey  Surveyor Guide Notes for Container Ship Survey  Surveyor Guide Notes for Sailing Yachts Survey.  Surveyor Guide Notes for Boat Marine Survey  Surveyor Guide Notes for Wooden Vessels Survey  Surveyor Guide Notes for Draft Survey

 Vernier Caliper.

 Surveyor Guide Notes for Towing Arrangement Survey...  Surveyor Guide Notes for MODU Towing Arrangements....  Surveyor Guide Notes for Bollard Pull Tests.

 Surveyor Guide Notes for Ship Stability, Inclining...  Surveyor Guide Notes for P&I insurance Surveys  Surveyor Guide Notes on Tailshaft Survey

 Surveyor Guide Notes on Tailshaft/Propeller Assemb...  Surveyor Guide Notes for Boiler Survey

 Surveyor Guide Notes for Marine Diesel Engine Surv...  Surveyor Guide Notes for Prepurchase Condition Sur...  Surveyor Guide Notes on Safety Construction Certif...  Surveyor Guide Notes on Safety Equipment Certifica...  Surveyor Guide Notes on Loadline Certificate Defic...  Surveyor Guide Notes on Marpol Certificate Deficie...  Surveyor Guideline Note on Hull Coating Inspection...  On/Off Hire Condition Survey

My Blog List

 Calculo Estructural del Buque

 Construcción del Buque I

 Estabilidad del Buque I

 Estabilidad del Buque II

Digital clock Links

(10)

 ABS

 American Club Mutual P&I Association  AWS online

 Binco

 Britannian Steam Ship  Bureau Veritas Veristar  Class NK

 DNV

 Equasis

 Estudios de Náutica

 European Maritime Safety Agency (EMSA)  Gard P&I

 General Cargo  GL Group  IACS

 INEA Venezuela

 Institute of Chartered Shipbrokers  Intercargo

 International Group of P&I Clubs  Intertanko

 Japan Coast Guard

 Japan Ship Owners' Mutual Protection & Indemnity Association  Lloyd Register of Shipping

 London Pandi  Marine Society

 NDE/NDT Resource Center  Paris MOU

 Ship Strcture Committe  Shipyards Directory  Skuld

 Steamship Mutual P&I Club  The ImarEST

 The Nautical Institute  The Standard Club  The Swedish Club  UK P&I Club  US Coast Guard  West of England P&I