[S&T HEX] Collar bolt application for extended tubesheet (API 660 & ASME)

 

[Shell and tube heat exchanger] Collar bolt application for extended tubesheet (API 660 & ASME)

---

1. API 660 para. 7.5.2.1

 

For a vertical heat exchanger where the stationary tubesheet is at the bottom, a suitable means of holding

the tube bundle in place shall be provided for when the bonnet or channel is removed. If collar bolts or drilled-and-

tapped holes are used, at least four shall be provided and their location shall be identified on the drawings and by

stamped markings on the OD of the tubesheet.

 

Vertical HEX 의 경우 bottom 의 bonnet 또는 channel 를 분리 시 tube bundle 의 position 을 잡기 위하여 collar bolt

또는 tapped hole 을 최소 4개 이상 제공해야 한다.

 

 

 

2. API 660, para 7.5.2.4

 

A full diameter stationary tubesheet shall be provided for removable tube bundle exchangers with bonnets

(see TEMA, Figure N-1.2, Type B stationary head). The tubesheet shall be provided with collar studs or tapped

tubesheet holes for a minimum of 25 % of the bolts (4 minimum). The tubesheet design shall allow for hydrostatic

testing of the shell side with the bonnet removed and all bolting installed.

 

Front end stationary head type 이 B (bonnet) 일 경우 tubesheet 는 full diameter 로 설계하여야 하며 최소 25% 의

Collar bolt 또는 tapped hole 을 제공하고 bundle 없이 hydrostatic test 가 가능하게 tubesheet 를 설계하여야 한다.

 

 

 

 

3. ASME VIII Div.1 UHX-9.5 Calculation for flanged extensions

 

(a) For flanged extensions that have bolt loads applied to them, the procedure for calculating the minimum required thickness of the extension, hr, is as follows.

 

Shell side hydro-test 시 collar bolt 체결을 위하여 Collar bolt depth 를 제외하고 남은 tubesheet 의 thickness 를 UHX-9.5 에 따라 hr 계산

 

 

 

 

4. 결론

 

1) Removable tube bundle 에 Type B bonnet 일 경우에는 tubesheet 를 full extension 시켜 설계하고 일반적으로 collar bolt 를 전체 tubesheet hole 에 적용하여 수압 test 가 가능하도록 설계 할 것.

 

2) Tubesheet 의 extended part 는 test condition 으로 collar bolt depth 를 제외한 thickness 를 verification 할 것.